Cook 3 minced garlic cloves and 1/2 teaspoon each minced rosemary and kosher salt in 2 tablespoons olive oil in a saucepan over medium heat, 1 minute. Add 1 cup orzo; toast, stirring, 2 minutes. Add one 14-ounce can cherry tomatoes and 2 cups chicken broth. Bring to a boil, then reduce the heat to low. Cover and cook, stirring, until the orzo is tender, 7 minutes. Stir in 2 tablespoons pecorino.