Cut boneless, skinless chicken breasts into 1-inch pieces. Season with salt and pepper. In a skillet, melt 2 tablespoons unsalted butter and 1 tablespoon olive oil over medium heat. Add 3 minced garlic cloves, 2 tablespoons Dijon mustard, juice and zest from 1 lemon, and 2 tablespoons chopped parsley, stirring until fragrant, about 2 minutes.

Increase heat to medium-high and add chicken pieces. Sear for 5-7 minutes until golden brown and cooked through (165°F). Remove chicken and leave browned bits in the pan.

In a pot, bring salted water to boil. Cook linguine according to package instructions until al dente, about 9-11 minutes. Reserve 1 cup pasta water before draining and toss pasta with olive oil.

In the same skillet, reduce heat to medium. Add 2 tablespoons unsalted butter, let melt and pick up browned bits. Stir in 1 teaspoon paprika and 1 teaspoon red pepper flakes, cooking for about 1 minute until fragrant. Deglaze with 1 cup chicken broth.

Once broth simmers for 3 minutes, lower heat and stir in heavy cream. Let simmer for another 2-3 minutes to thicken. Whisk in ½ cup grated Parmesan cheese until smooth and adjust seasoning.

Return chicken to skillet, add drained linguine, and toss to coat in sauce, adding reserved pasta water as necessary. Serve hot, garnished with parsley and additional Parmesan.