Boil chicken until cooked through.

Set chicken aside and use the broth to cook spaghetti noodles.

Place cooked noodles in a greased rectangular pan.

Shred the cooked chicken and distribute it over the noodles.

Chop onion and green pepper.

Sauté the chopped onion and green pepper in butter until softened.

Layer the sautéed onion and pepper mixture on top of the chicken and noodles.

Pour evaporated milk evenly over the ingredients in the pan.

Chop Velveeta cheese into chunks and add it to the evaporated milk in the pan.

Continuously stir the Velveeta cheese and evaporated milk mixture over medium heat until it forms a smooth cheese sauce.

Pour the cheese sauce over the noodle, chicken, onion, and pepper mixture.

Bake in a preheated oven at 350°F (175°C) for approximately 30 minutes.

Optionally, top with Ritz crackers or shredded cheese.

If topping, bake for an additional 5 minutes until the topping is golden brown and the cheese is melted.