Fra diavolo means “brother devil”—a hint that this shrimp dish is spicy. Grace Parisi gives the shrimp extra flavor by first marinating it quickly in olive oil with crushed red pepper. Slideshow: Italian Seafood
In a medium bowl, toss the shrimp with 2 tablespoons of the olive oil and the crushed red pepper; season with salt and black pepper. Let stand for 20 minutes.
Heat a large skillet until very hot. Add the shrimp and cook over high heat until lightly browned and nearly cooked through, about 2 minutes. Transfer the shrimp to a plate.
Add the remaining 2 tablespoons of olive oil to the skillet along with the pancetta, onion and garlic and cook over high heat, stirring occasionally, until lightly browned, about 4 minutes. Return the shrimp and any accumulated juices to the skillet. Add the marinara sauce and simmer over moderate heat until the shrimp are cooked through, about 2 minutes. Transfer the shrimp to bowls, garnish with the parsley and serve with crusty bread.