Cook the Macaroni

• Bring a large pot of salted water to a boil.
• Add the elbow macaroni and cook according to the package instructions until al dente.
• Reserve ¼ cup of pasta water, then drain the pasta and set aside.

Season the Chicken

• Place the chicken pieces in a bowl.
• Add the chili powder, smoked paprika, cumin, garlic powder, onion powder, salt, and black pepper.
• Toss until the chicken is evenly coated with the seasoning.

Cook the Chicken

• Heat 1 tablespoon of olive oil in a large skillet over medium-high heat.
• Add the seasoned chicken in a single layer.
• Cook for 6–8 minutes, stirring occasionally, until golden brown and the internal temperature reaches 165°F (74°C).
• Transfer the cooked chicken to a plate and set aside.

Prepare the Fajita Vegetables

• Add another tablespoon of olive oil to the same skillet.
• Add the sliced bell peppers and onion.
• Cook for 4–5 minutes, stirring occasionally, until softened but still slightly crisp.
• Stir in the minced garlic, chili powder, and cumin.
• Cook for another 30 seconds until fragrant.
• Remove the vegetables from the skillet and set aside with the chicken.

Make the Creamy Cheese Sauce

• Reduce the heat to medium and melt the butter in the skillet.
• Whisk in the flour and cook for about 1 minute, stirring constantly.
• Gradually pour in the milk and heavy cream, whisking continuously until smooth.
• Add the Dijon mustard, smoked paprika, and garlic powder.
• Simmer gently for 3–5 minutes, stirring until the sauce thickens.
• Reduce the heat to low and gradually stir in the cheddar and Monterey Jack cheese until melted and creamy.
• Season with salt and black pepper to taste.

Combine Everything

• Add the cooked macaroni to the cheese sauce and stir until well coated.
• Return the chicken and fajita vegetables to the skillet.
• Toss gently until everything is evenly combined.
• Add a little reserved pasta water if the sauce is too thick.
• Allow everything to warm together for 2–3 minutes over low heat.

Garnish and Serve

• Remove from the heat and sprinkle with fresh cilantro and sliced green onions.
• Add extra shredded cheese and a squeeze of fresh lime juice if desired.
• Serve immediately while warm, creamy, and cheesy.