Cook the pasta: Bring a large pot of salted water to a boil. Cook spaghetti until just shy of al dente (about 1 minute less than the package says). Drain and set aside. Toss with a drizzle of olive oil to prevent sticking.

Sauté aromatics: In a large skillet or Dutch oven, heat butter and olive oil over medium. Add onion and bell pepper. Cook 5–6 minutes, stirring, until softened. Add garlic and cook 30 seconds until fragrant.

Build the sauce base: Stir in smoked paprika, garlic powder, onion powder, cayenne (if using), and a pinch of salt and pepper. Toast spices for 15–20 seconds.

Add liquids and melt-ins: Pour in chicken broth and add the condensed cream of chicken soup. Stir until smooth. Add cream cheese cubes and stir until melted and creamy.

Stir in chicken and tomatoes: Add shredded chicken and drained diced tomatoes with green chilies. Simmer gently for 2–3 minutes. If it seems too thick, splash in a bit more broth.

Make it cheesy: Lower the heat and add 1.5 cups of shredded cheddar in small handfuls, stirring as it melts. Keep the heat low to prevent clumping or graininess.

Combine with pasta: Add the cooked spaghetti to the sauce. Toss until every strand is coated and the mixture looks creamy and unified. Taste and adjust salt and pepper.

Optional bake: For a bubbly, browned top, transfer everything to a lightly greased 9x13-inch baking dish. Sprinkle the remaining 0.5 cup cheddar on top. Bake at 375°F (190°C) for 12–15 minutes until melted and lightly golden. Rest 5 minutes before serving.

Finish and serve: Garnish with chopped parsley or green onions. Serve hot with a simple green salad or steamed veggies.