Stuffed Pepper Casserole

Ingredients

Dry and pantry:

• 1 cup long-grain white rice (or ¾ cup brown rice, increase liquid by 15–20 minutes cooking)
• 1 can (14–15 oz) diced tomatoes with juices
• 1 can (6 oz) tomato paste or ¾ cup tomato sauce
• 1½ cups beef or chicken broth (low-sodium preferred)
• 1–2 tsp Worcestershire sauce (optional, for depth)

Produce and fresh:

• 4–6 bell peppers (mixed colors; aim for uniform size)
• 1 medium yellow onion, finely diced
• 2–3 garlic cloves, minced
• Optional garnish: fresh parsley or chopped chives

Protein and dairy:

• 1 lb ground beef (80/20 for flavor; sub ground turkey or plant-based crumbles)
• 1½ cups shredded cheddar or Mexican blend, divided
• Salt and pepper to taste; use 1½ tsp kosher salt and ½ tsp black pepper as a starting point
• 1 tsp smoked paprika, 1 tsp dried oregano, ½ tsp crushed red pepper (optional)

Tips:
Use parboiled rice for fastest results or precook rice 10 minutes less than package to finish in the oven; reserve a small splash of broth to adjust consistency before baking.

Gathering Ingredients and Selecting Peppers

Choose peppers by shape and thickness:

• Look for uniform, firm bell peppers with flat bottoms so they sit upright in the casserole; if using smaller peppers, plan for 6–8, larger peppers 4–5.
• Avoid peppers with soft spots; a firmer pepper holds filling without collapsing during baking.

Protein and rice considerations:

• For richer flavor use 80/20 ground beef; for leaner version use 93/7 and add 1 tbsp olive oil to pan during browning.
• If using pre-cooked rice, drain and fluff; if using quick-cook rice, reduce oven liquid slightly and check early.

Cheese and sauce:

• Reserve about ½ cup cheese to sprinkle on top near the end of bake for a golden crust.
• If tomatoes are very watery, drain a bit to avoid excess liquid; you can always add broth while assembling.

Practical prep tips:
Have a colander, chef's knife, and a 9x13-inch baking dish ready; measure liquids into a liquid measuring cup so you can adjust for parboiled vs. raw rice. If stuffing hollowed peppers into a single casserole dish rather than stuffing individually, choose peppers that will nest without large gaps to minimize sauce pooling.

Preheat, Pan Choice, and Oven Setup

Set temperature and rack:
Preheat oven to 375°F (190°C) for even baking; use the center rack for the most consistent heat. If the casserole contains a lot of raw rice, raise temperature to 400°F (200°C) and reduce baking time by 10–15 minutes while checking liquid level.
Pan material and size:
Use a 9x13-inch glass or ceramic baking dish for even heat distribution and easier serving; for deeper casseroles a 3-quart round or square dish works but expect 5–10 extra minutes of bake time. Metal pans brown edges faster—reduce temperature by 25°F if using thin metal.
Lining and foil:
Lightly grease the dish with 1 tbsp oil or cooking spray; cover tightly with foil for the majority of bake time to trap steam and finish uncovered for browning. Use foil tenting if cheese is browning too fast.
Oven thermometer and probe:
If available, insert an oven-safe probe into the center of the casserole to monitor internal temperature; finished internal temperature for ground beef filling should reach 160°F (71°C). Allow 5–10 minutes post-bake resting to allow juices to settle before slicing.

Preparing the Peppers

Trimming and hollowing:
Trim the top of each bell pepper to create a straight edge and remove the seeds and membranes with a small spoon. For casseroles where peppers will lay on their sides, slice peppers in half lengthwise and remove ribs; for upright stuffed pepper-style, leave bottoms intact to hold filling.
Blanching vs. raw:
To soften peppers before baking, blanch halves or whole peppers in boiling water for 2 minutes then shock in ice water; drain completely. Blanching reduces total bake time and prevents a raw crunchy center. If you prefer firmer peppers, skip blanching—raw peppers will hold more texture but may require longer bake time to soften.
Sizing and evenness:
Select peppers similar in size so they cook evenly. If sizes vary, place smaller peppers on the outer edges of the dish where heat intensity can be slightly higher. Trim any overly thick ribs inside to increase filling capacity.
Drying and oiling:
Pat peppers dry after washing or blanching; brush interior with a teaspoon of olive oil and sprinkle with a pinch of salt to draw out moisture and encourage tender flesh during baking. For stuffed halves, place cut side up initially to hold filling; for whole peppers placed upright, pack filling tightly but don't overstuff—leave a ¼-inch clearance at the top for rice expansion and cheese.

Cooking the Filling and Flavor Building

Sear and render:
Heat a large skillet over medium-high heat with 1 tbsp neutral oil; add ground beef and break into small pieces. Brown until caramelized edges appear—this creates flavor via the Maillard reaction. Drain excess fat leaving about 1 tbsp for sautéing aromatics.
Aromatics and deglazing:
Add diced onion and cook 4–5 minutes until translucent, then add minced garlic and cook 30–45 seconds. Sprinkle in smoked paprika, dried oregano, and a pinch of crushed red pepper. Deglaze with 2 tbsp of broth or red wine to lift fond from the pan; scrape with a wooden spoon.
Tomato base and rice:
Stir in diced tomatoes with juices and tomato paste; incorporate the rice and 1 to 1¼ cups of broth depending on rice type. Bring to a simmer and cook 5–7 minutes—rice should be partially cooked (al dente) so it finishes in the oven without turning mushy.
Season and taste:
Season with salt and pepper, 1–2 tsp Worcestershire sauce for umami, and a teaspoon of sugar only if tomatoes taste too acidic. Fold in 1 cup of shredded cheese off heat to bind filling. Test a small spoonful: the filling should be well-seasoned, slightly saucy but not soupy; if too dry add 2–4 tbsp broth.

Assembling the Casserole

Combine and adjust consistency:
Transfer the cooked filling to a mixing bowl; if the mixture seems very wet, let it rest 3–4 minutes—rice will absorb some liquid. Adjust seasoning with extra salt, pepper, or a splash of broth if it feels dry.
Layering methods:
Method A (pepper halves): Lay pepper halves cut side up in a greased 9x13-inch dish and spoon the filling into each half, mounding slightly; tuck loose rice into gaps to avoid empty pockets. Method B (arranged whole peppers): Pack filling into whole peppers standing upright; if peppers wobble, nestle them together so sides touch to support upright position. Method C (deconstructed casserole): Scatter a thin layer of filling across the dish, place pepper rings or chunks on top, then add remaining filling and finish with cheese—this creates a more baked, unified texture.
Cheese and topping:
Sprinkle remaining ½ cup cheese evenly over the dish. For a crisp topping mix 2 tbsp panko with 1 tbsp melted butter and sprinkle for crunch. For herb brightness add chopped parsley or basil after baking rather than before to retain color.
Final checks before baking:
Ensure filling level is below the pepper rim by about ¼ inch to prevent overflow, and pour any remaining tomato-broth mixture around peppers to add steam and prevent dryness.

Baking, Timing, and Resting

Covered vs. uncovered baking:
Start baking covered with foil for the first 25–35 minutes to steam rice and soften peppers; this traps moisture and prevents the top from drying. Remove foil during the last 10–15 minutes to brown cheese and crisp edges. Use foil tenting if cheese melts too quickly.
Time guidelines:
For partially cooked rice and blanched peppers, bake 25–30 minutes at 375°F. For raw rice and raw peppers, bake 40–50 minutes at 375°F; check rice for tenderness after 35 minutes. If total volume is large, increase bake time by 5–10 minutes and check internal temperature of filling (160°F / 71°C for ground beef).
Moisture control during bake:
If casserole appears dry midway, add ¼ cup hot broth around edges and replace foil. If too watery after baking, remove foil and bake uncovered 5–10 minutes to evaporate excess liquid.
Resting and serving:
Remove from oven and rest uncovered 10–15 minutes to let gravy thicken and make slicing neater. Garnish with fresh herbs. For individual servings, use a slotted spoon to lift peppers and drain excess juices; for a sliced casserole, let rest until internal juices set to avoid collapse when cutting.

Variations, Substitutions, and Make-Ahead Tips

Protein swaps and vegetarian options:
Substitute ground turkey or chicken for beef and add 1 tbsp olive oil during browning to compensate for leaner meat. For a vegetarian version use cooked lentils or crumbled tempeh; increase tomato paste and broth slightly for moisture and finish with grated aged cheese or vegan cheese.
Grain alternatives and low-carb:
Swap rice for cooked quinoa (1:1 by volume) or cauliflower rice for a low-carb option; if using cauliflower rice, reduce oven liquid and decrease initial covered bake time by 10 minutes. For brown rice increase liquid by 25% and expect longer bake times.
Herb and spice variations:
Add cumin and coriander for a Mexican-inspired profile, or smoked paprika and thyme for a Mediterranean twist. Fold in chopped olives or capers for briny notes, or stir in a splash of balsamic for sweetness balance.
Make-ahead and freezing:
Assemble casserole fully, cover, and refrigerate up to 24 hours; increase baking time by 5–10 minutes from chilled. For freezing, assemble without final cheese topping, freeze in an airtight container up to 3 months; bake from frozen at 375°F for 50–70 minutes, covered initially, then uncover to brown.
Serving suggestions:
Serve with a crisp green salad, crusty bread to soak up juices, or a dollop of Greek yogurt for tang. Leftovers reheat well in a 350°F oven covered for 15–20 minutes or in a microwave until piping hot.

FAQs

Is parboiled rice necessary?
Parboiled rice is not necessary but speeds finishing in the oven; if using raw long-grain rice, partially cook it in the filling for 5–7 minutes before assembling so it reaches tenderness during baking.
Can I make this dairy-free?
Yes—omit cheese or use a dairy-free shred that melts. Add 1–2 tbsp nutritional yeast for savory depth and adjust salt to taste.
How do I avoid watery casserole?
Drain very wet canned tomatoes slightly, do not over-add broth, and ensure rice is partially cooked rather than raw. Rest the casserole after baking to allow liquids to thicken.
What internal temperature indicates doneness?
For ground beef or mixed meat fillings aim for 160°F (71°C); rice should be tender without a starchy core.
Can I cook this in a slow cooker?
Yes—brown filling first, combine all ingredients (use 1:1.25 rice-to-liquid ratio for white rice) and cook on low 3–4 hours; add cheese in the last 15 minutes.
How to reheat leftovers?
Reheat individual portions in a 350°F oven covered for 15–20 minutes, or microwave on high in 60-second bursts until hot. Add a splash of broth if dry.
Can I double the recipe?
Yes—use two 9x13 dishes or a larger roaster. Bake time may increase slightly; check rice doneness and internal temperature as indicated above.