1Cook the elbow macaroni in salted boiling water until al dente. Drain and set aside, reserving 1/2 cup of pasta water.
2Toss the thinly sliced chicken breast with chili powder, smoked paprika, cumin, onion powder, garlic powder, salt, and pepper.
3Heat olive oil in a skillet over medium-high heat. Add the seasoned chicken and cook until browned and cooked through, about 5–7 minutes. Remove and set aside.
4In the same skillet, add the sliced red, green, and yellow bell peppers and red onion. Sauté until softened and slightly charred, about 5–6 minutes. Set aside.
5In a large pot, melt butter over medium heat. Stir in flour and cook for 1 minute.
6Gradually whisk in milk and heavy cream. Simmer until the mixture thickens.
7Add shredded cheddar, Monterey Jack cheese, smoked paprika, and salt. Stir until the cheese is melted and the sauce is smooth.
8Add the cooked macaroni to the cheese sauce. Fold in the cooked chicken and sautéed vegetables. Stir until everything is well coated.
9If the sauce is too thick, add reserved pasta water as needed to reach desired consistency.
10Optional: Top with extra cheese and broil for 2–3 minutes until golden and bubbly.
11Garnish with cilantro, jalapeños, or lime if desired. Serve hot.