Preheat and Prep: Start by preheating your oven to 350°F. In a large pot, bring 2 quarts of water to a boil and add 1 tablespoon of salt for the egg noodles.

Prepare the Tomato Sauce: Heat 1 tablespoon of olive oil in a large, heavy-bottomed pot over medium-high heat. Add the chopped onions and bell peppers, sautéing for about 4 minutes until softened. Stir in the minced garlic and cook for an additional minute. Add the tomatoes (breaking them up by hand if using whole tomatoes), bring to a simmer, and cook for 10 minutes. Lower the heat to keep it warm.

Brown the Beef: In a separate skillet, heat the remaining tablespoon of oil over medium-high heat. Add the ground beef in batches to avoid crowding the pan. Let the meat sit for a minute or two without stirring to achieve a nice brown crust. Sprinkle with 1/2 teaspoon of salt. Once browned on both sides, transfer the beef into the tomato sauce mixture.

Sauté the Mushrooms: Use the same skillet with the remaining beef drippings to sauté the sliced mushrooms. Once they are browned and tender, add them to the beef and tomato mixture.

Cook the Noodles: While the mushrooms are cooking, drop the egg noodles into the boiling water. Cook for 4 to 5 minutes until they are al dente (slightly firm). Drain the noodles well.

Assemble the Casserole: In a large 3-quart casserole dish, combine the cooked egg noodles with the tomato and beef mixture. Stir in the corn, chopped olives, and approximately two-thirds of the grated cheddar cheese.

Bake: Sprinkle the remaining cheese over the top of the casserole. Place it in the oven and bake uncovered at 350°F for 30 minutes until the cheese is melted and bubbly.