01 - Cook the pasta in a large pot of salted boiling water according to package instructions until al dente. Drain and set aside, reserving 1/2 cup pasta water.
02 - Heat 1 tablespoon butter in a large skillet over medium-high heat. Add the chicken pieces, season with salt and pepper, and sauté until golden and cooked through, about 5-6 minutes. Remove chicken to a plate and set aside.
03 - In the same skillet, add red and yellow bell peppers, and red onion. Sauté for 3-4 minutes until softened. Add garlic and cook for 1 minute until fragrant.
04 - Reduce heat to medium. Add remaining butter, Dijon mustard, lemon juice, Worcestershire sauce, hot sauce, smoked paprika, crushed red pepper flakes, oregano, parsley, and chives. Stir until melted and aromatic.
05 - Pour in the heavy cream and Parmesan cheese. Stir until the sauce is smooth and creamy.
06 - Return the cooked chicken to the skillet, add spinach, and cook until wilted, about 1 minute.
07 - Add the drained pasta, tossing to coat in the sauce. If the sauce is too thick, add a splash of reserved pasta water until desired consistency is reached.
08 - Taste and adjust seasoning with salt, pepper, and extra lemon juice if desired. Serve hot, garnished with extra herbs and Parmesan cheese if desired.