Cook the spaghetti according to package instructions until al dente. Drain and set aside.

In a large skillet, heat the olive oil over medium heat. Add the chicken pieces, garlic powder, onion powder, paprika, salt, and pepper. Cook until the chicken is browned and cooked through, about 5-7 minutes.

Add the diced bell peppers and onion to the skillet. Sauté for an additional 3-4 minutes until the vegetables are tender.

Stir in the diced tomatoes and chicken broth. Bring to a simmer and cook for 5 minutes.

Reduce the heat to low and add the cooked spaghetti, cheddar cheese, and sour cream. Stir until the cheese is melted and everything is well combined. Cook for another 2-3 minutes until heated through.

Garnish with chopped parsley if desired and serve warm.