Preheat the oven to 350°F

Place the ground beef in a large cast-iron skillet. After it has browned, remove the meat from the skillet and let it cool.

Mix the ground beef with the oil and cook until the crust is formed on approximately 50 to 60 percent of the beef.

You can remove the beef, but you can also leave the fat. Add the butter, the onions, and bell peppers.

Brown for 1-2 min, stirring then brown for 1-2 min again.

Return the beef to the pan.

Stir the Worcestershire sauce, ketchup, salt, and black pepper into a saucepan.

Remove it from the heat and add it to the pasta shells.

Each shell should be topped with cheese cubes (use half of the cheese).

In the same saucepan, add the beef broth and milk. Stir well before turning off the heat.

Mix in the remaining cheddar cheese one at a time and whisk for 3 to 5 minutes or till thickened.

Use about half of the sauce to coat the shells.

To melt the cheese, bake in the oven for ten minutes

Serve with any remaining sauce.