Bring a large pot of salted water to a rolling boil. Once boiling, add pasta and cook until al dente, about 8-10 minutes. Drain pasta, reserving about a cup of pasta water.

Slice chicken breasts into 1-inch strips and season with salt and pepper. Dredge in flour.

Heat 2 tbsp of butter and 1 tbsp of olive oil in a skillet. Add chicken strips and cook for 3-4 minutes on each side until golden brown. Remove chicken and set aside.

In the same skillet, reduce heat and add minced garlic. Sauté for about 30 seconds until fragrant.

Pour in 1 cup of chicken broth, 2 tbsp of lemon juice, and 1 tbsp of Dijon mustard. Scrape the pan and add Italian seasoning and red pepper flakes. Simmer for 1 minute.

Return chicken to skillet and add 1 cup of heavy cream and spinach. Stir until spinach wilts, about 2-3 minutes.

Add drained pasta and ½ cup of grated Parmesan cheese. Toss until pasta is coated. Add reserved pasta water if sauce is too thick. Adjust seasoning as needed.