Step 2
Melt the butter in a large skillet over medium-high heat. Add the shrimp in a single layer and cook for about 1-2 minutes per side until just cooked through. They will be added to the sauce after, so make sure not to overcook. Remove and set aside.
Step 3
Add the olive oil to the skillet. Once hot add the onions and cook for 4-6 minutes until beginning to soften. Add the garlic and cook for 1 minute.
Step 5
Add the tomatoes, Calabrian chilies (or red pepper flakes), and Italian seasoning. Bring to a simmer and cook for 10 minutes. It should thicken slightly. Taste and adjust heat level if needed.
Step 6
Add the shrimp to the sauce and cook for about one minute. Garnish with fresh parsley and basil. Shrimp Fra Diavolo is traditionally served with pasta.