Bring a large pot of salted water to a boil and cook the spaghetti according to package instructions.

In a large pot or Dutch oven, heat the olive oil over medium heat. Add the diced chicken and cook until browned and cooked through, about 5-7 minutes, stirring occasionally.

Stir in the onion and bell pepper, cooking until softened, about 3-4 minutes.

Add the minced garlic and sauté for another minute.

Pour in the diced tomatoes with green chilies, chicken broth, chili powder, cumin, salt, and pepper.

Once the pasta is done, drain it and add it to the pot with the chicken and sauce.

Stir in the sour cream and half of the cheddar cheese until creamy and well mixed.

Sprinkle the remaining cheese on top and let it melt for a few minutes. Serve warm.