Preheat the oven to 375°F (190°C). Slice the tops off the bell peppers and remove seeds and membranes. If necessary, trim a thin slice from the bottom so peppers sit upright, being careful not to create a hole. Lightly brush the insides and outsides with 1 teaspoon olive oil and set upright in a 9x13-inch baking dish.

Cook rice

Rinse 1 cup long-grain rice under cold water until water runs clear. In a small pot, bring 1 cup broth to a boil, add the rice, reduce heat to low, cover and simmer 15 minutes or until just tender and liquid is absorbed. Remove from heat and let sit covered 5 minutes, then fluff with fork.

Cook lamb filling

While rice cooks, heat 2 tablespoons olive oil in a large skillet over medium-high heat. Add finely diced onion and sauté 4–5 minutes until soft and translucent. Add minced garlic and cook 30 seconds until fragrant. Add 1 pound ground lamb and break up with a spoon; cook 6–8 minutes until browned and no longer pink. Drain any excess fat if needed.

Season and combine

Stir into the browned lamb: 2 tablespoons tomato paste, 1 teaspoon ground cumin, 1 teaspoon dried oregano, 1 teaspoon smoked paprika, 1/4 teaspoon ground cinnamon, 1 teaspoon salt and 1/2 teaspoon black pepper. Cook 1–2 minutes to toast the spices. Add the can of diced tomatoes (with juices) and simmer 4–5 minutes to meld flavors and reduce slightly. Stir in the cooked rice and 1 tablespoon chopped parsley, mixing until evenly combined. Taste and adjust seasoning (salt/pepper) as needed.

Stuff peppers

Spoon the lamb and rice mixture into each prepared bell pepper, packing gently but leaving a little room at the top for sauce. You should have enough filling for four large peppers.

Sauce & Bake

Make the baking sauce by whisking together 1 cup tomato sauce (or passata), 1/2 cup water and 1 tablespoon lemon juice. Pour about 1/2 cup of the sauce into the bottom of the baking dish around the peppers (not overfilling the peppers). Drizzle remaining 1 teaspoon olive oil lightly over the peppers and top (optional) with 1/2 cup crumbled feta or 1/2 cup shredded Parmesan.

Cover the dish tightly with foil and bake in the preheated 375°F (190°C) oven for 35 minutes. Remove foil and continue baking 10–15 minutes more until peppers are tender and filling is heated through and cheese (if used) is browned lightly. Internal temperature of filling should read at least 165°F (74°C).

Remove from oven and let rest 5–10 minutes. Spoon remaining sauce from the pan over each stuffed pepper and garnish with the remaining chopped parsley. Serve warm.