01 - Preheat oven to 375°F. Lightly grease a 9x13 inch baking dish with cooking spray or butter.
02 - Cook egg noodles according to package directions until al dente. Drain thoroughly in a colander and set aside.
03 - Heat olive oil in a large skillet over medium heat. Add diced onion and red bell pepper if using; sauté for 3–4 minutes until softened and fragrant.
04 - Add ground beef to the skillet and cook until browned, breaking up with a spatula as it cooks. Drain excess fat from the pan.
05 - Stir in minced garlic and cook for 1 minute until aromatic. Add tomato paste, drained tomatoes, frozen peas if using, Italian herbs, paprika, salt, and pepper. Simmer for 3–4 minutes to meld flavors.
06 - Remove skillet from heat. Mix in sour cream and cream of mushroom soup until fully incorporated and smooth.
07 - Fold in half of the shredded cheddar cheese and the cooked noodles. Stir gently until evenly distributed throughout the beef mixture.
08 - Transfer the mixture to the prepared baking dish, spreading evenly. Top with the remaining cheddar cheese in a uniform layer.
09 - Bake for 25–30 minutes until cheese is melted, golden, and bubbly around the edges. Let rest for 5 minutes before serving to allow the casserole to set.