Preheat your oven to 350°F (175°C) and grease a large baking dish.

In a large skillet, heat olive oil over medium heat. Add the diced onion and red bell pepper, cooking until they soften, approximately 5 minutes.

Add minced garlic to the skillet and cook for an additional minute until fragrant.

Next, add the ground beef to the skillet. Break it up with a spatula and cook until browned, about 6-8 minutes. Drain any excess fat.

Stir in ketchup, Worcestershire sauce, mustard, chili powder, salt, and pepper. Let the mixture simmer for about 5 minutes.

In another pot, cook the macaroni according to package instructions until al dente. Drain and add it to the meat mixture, stirring well to combine.

In a separate bowl, whisk together the milk and eggs. Pour this mixture over the macaroni and meat, ensuring everything is evenly coated.

Gently fold in 1 cup of shredded cheddar cheese into the mixture.

Transfer the casserole mixture to the prepared baking dish. Sprinkle the remaining shredded cheese on top, followed by the breadcrumbs.

Cover the dish with aluminum foil and bake for 25 minutes.

Remove the foil and bake for an additional 15 minutes, or until the cheese is bubbly and the top is golden brown.

Remove the casserole from the oven and let it cool for a few minutes. Garnish with chopped parsley before serving.