1. Bring a large pot of salted water to a boil and cook pasta until al dente. Reserve 1/2 cup pasta water, then drain.

2. Heat oil in a nonstick skillet over medium-high heat. Season chicken with salt, pepper, and smoked paprika. Sear until golden and cooked through, about 5 minutes. Remove chicken and keep warm.

3. Reduce heat to medium-low. Melt butter in the same skillet, stirring in garlic until fragrant.

4. Whisk in Dijon mustard, lemon juice, and zest. Add red-pepper flakes and half the parsley.

5. Return chicken to the pan and coat with sauce.

6. Add drained pasta and toss with tongs, adding reserved pasta water a little at a time until sauce is glossy and clings to noodles. Stir in cream if desired.

7. Adjust seasoning with lemon or butter as needed.

8. Serve immediately topped with remaining parsley and Parmesan.