Minestrone with Gnocchi

Name: Minestrone with Gnocchi
Ingredients: 3 tablespoons extra-virgin olive oil, plus more for drizzling; 2 stalks celery, chopped; 2 carrots, chopped; 1 onion, chopped; Kosher salt and freshly ground pepper; 2 cloves garlic, minced; 1/4 teaspoon red pepper flakes; 1 15-ounce can diced tomatoes; 1 small sprig rosemary; 1/3 cup grated parmesan cheese, plus 1 small parmesan rind (optional); 1 small head escarole, chopped; 1 16-ounce package gnocchi