Preparation Puree 1/2 cup oil, onion, garlic, salt, and pepper in blender until almost smooth. Place shrimp in small bowl. Stir in oil mixture. Let shrimp marinate 1 hour. Heat remaining 1/4 cup oil in heavy large skillet over high heat. Add shrimp with marinade and sauté just until shrimp are opaque in center, about 4 minutes. Divide shrimp and marinade from skillet among 4 plates and serve.