Hearts of Palm Parm

Name: Hearts of Palm Parm
Ingredients: Three 14-ounce cans whole hearts of palm, drained; Kosher salt; 1/2 cup extra-virgin olive oil; 1 large yellow onion, 1/4-inch dice; 6 cloves garlic, minced; One 28-ounce can crushed tomatoes; One 14-ounce can diced tomatoes; Pinch crushed red pepper flakes; 1 1/2 teaspoons fish sauce, optional; 1 1/4 cups finely grated Parmesan (about 3 ounces); Hand-torn fresh basil leaves, for garnish; 1 1/2 cups quick-cooking polenta, cooked according to the package directions, warm