Prepare fettuccine according to package directions. Drain, reserving ½ cup pasta water.

In a large skillet, melt 4 tablespoons butter and add in minced garlic. Cook shrimp in the garlic butter, 2 minutes per side. Remove shrimp from skillet and set aside.

Reduce heat to medium and add diced onion and cut red bell pepper into the skillet, cooking for about 10 minutes, until onions are translucent.

Add salt, pepper and dried parsley to the skillet, along with 2 cups half and half. Stir to combine and bring to a simmer. Let simmer for about 5 minutes, until cream starts to thicken and take on the flavors of the skillet.

Add in fresh spinach and cook down, until spinach is wilted. Stir in fresh-grated parmesan and pinch of red pepper flakes. If sauce is too thick, thin out with reserved pasta water.

Return pasta and shrimp to the pan, folding in the ingredients to combine and coat evenly.

Serve.