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

In a large skillet, heat olive oil and sauté the chicken breasts for 6-7 minutes per side until golden brown. Shred the chicken once cooked.

Boil salted water and cook the spaghetti until al dente, about 8-10 minutes. Drain and cool briefly.

In a mixing bowl, combine shredded chicken, spaghetti, cream of chicken soup, bell peppers, paprika, cayenne pepper, garlic powder, and half of the cheddar cheese, mixing well.

Transfer the mixture to the greased casserole dish and top with the remaining cheddar cheese. Bake for 25-30 minutes until bubbly and golden brown.

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