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

Heat olive oil in a large pot over medium heat, then cook chicken for 6-7 minutes on each side until golden brown.

In a separate pot, boil salted water and cook spaghetti for 8-10 minutes until al dente.

Combine shredded chicken, cooked spaghetti, cream of chicken soup, chopped bell peppers, paprika, cayenne pepper, garlic powder, and half of the cheddar cheese in a mixing bowl.

Transfer the mixture to the casserole dish and top with remaining shredded cheese.

Bake for 25-30 minutes until cheese is bubbly and golden brown.

Let the casserole rest for 5 minutes, then garnish with sliced green onions before serving.