Start by slicing your chicken breasts into thin, even strips.

In a small bowl, mix together your chili powder, smoked paprika, cumin, garlic powder, onion powder, cayenne pepper, salt, and black pepper. Toss your chicken strips into this spice blend and make sure every piece is well coated.

Heat a large skillet or cast iron pan over medium-high heat. Add your olive oil and let it get nice and hot.

Add the seasoned chicken strips in a single layer. Cook them for about 3 to 4 minutes on one side without moving them.

Flip and cook for another 2 to 3 minutes until fully cooked through. Remove the chicken and set aside.

In the same pan, add a tiny drizzle more olive oil if needed and toss in your sliced bell peppers and onion.

Cook over medium-high heat for about 5 to 6 minutes, stirring occasionally.

Season lightly with a pinch of salt, pepper, and a small dusting of chili powder.

In a large saucepan, melt your butter over medium heat.

Once melted, add the flour and whisk constantly for about 1 minute.

Slowly pour in the milk and whisk to prevent lumps. Add the chicken broth and keep whisking until the mixture starts to thicken.

Lower the heat to medium-low, add the cream cheese, then add the shredded cheddar and Monterey Jack in two batches.

Stir in the mustard powder, salt, and pepper, and adjust seasoning as needed.

Bring a large pot of salted water to a boil. Cook your pasta according to the package instructions until one minute before al dente.

Drain the pasta and add it directly into your cheese sauce, stirring well to coat.

Add your cooked fajita chicken strips and sautéed vegetables into the pasta and cheese sauce. Fold everything together gently.

Adjust seasoning if needed and serve hot with your favorite toppings.