Cook pasta till al dente and reserve 1 cup pasta water.
Heat a large deep sided pan over medium high heat with olive oil, 2 tbsp butter and chili flakes.
Add cubed chicken. Season with salt and pepper. Brown chicken on all sides and set aside.
Add shrimp, season, and cook until pink on both sides. Set aside.
Deglaze pan with Prosecco and add onion. Cook for several minutes then add garlic. Cook until fragrant.
Pour in cream. Use spatula or wooden spoon to mix stirring up all the bits from the bottom of the pan.
Add in tomato sauce and stir to combine.
Bring to a simmer before adding in chicken and shrimp.
Toss to coat in the sauce. Add in cooked pasta and spinach and remaining butter.
Pour approximately 1/2 cup pasta water into pasta to help emulsify the sauce.
Season with cheese, salt, cracked pepper and more chili flakes if desired.