Shrimp Puttanesca

Name: Shrimp Puttanesca
Ingredients: 2 tablespoons extra-virgin olive oil, divided; 1 small yellow onion, chopped; 3 garlic cloves, minced; 3 anchovy filets, finely chopped; 1 teaspoon crushed red chili flakes, divided; 2 cups grape or small cherry tomatoes; 1/3 cup oil cured olives, pitted, coarsely chopped; 1/2 cup dry white wine; 2 teaspoons capers, rinsed; 1/2 teaspoon sugar, optional; 1 pound medium shrimp, shelled and deveined; 1/2 teaspoon salt; 1/4 cup chopped fresh Italian parsley