Step 1: Cook the pasta
- Bring a large pot of salted water to a boil and cook the pasta according to the package instructions until al dente. Reserve 1/4 cup of the pasta water, then drain and set aside.
Step 2: Cook the chicken
- Heat the olive oil in a large skillet over medium heat.
- Season the diced chicken with garlic powder, onion powder, smoked paprika (if using), salt, and black pepper.
- Add the chicken to the skillet and cook for 5-7 minutes, stirring occasionally, until browned and cooked through. Remove the chicken from the skillet and set aside.
Step 3: Make the cheese sauce
- In the same skillet, melt the butter over medium heat. Add the flour and whisk continuously for 1-2 minutes to create a roux.
- Gradually pour in the milk, whisking constantly to avoid lumps. Cook for 3-4 minutes until the sauce thickens slightly.
- Stir in the shredded cheddar, Parmesan cheese, and Dijon mustard (if using). Mix until the cheese is melted and the sauce is smooth.
Step 4: Combine the pasta and chicken
- Add the cooked pasta and chicken back into the skillet with the cheese sauce. Toss until everything is evenly coated.
- If the sauce is too thick, add the reserved pasta water, 1 tablespoon at a time, until you reach your desired consistency.
Step 5: Garnish and serve
- Serve the cheesy chicken pasta hot, garnished with chopped parsley if desired.