Creamy Vegetable Soup

Name: Creamy Vegetable Soup
Prep time: 30 min
Cook time: 23 min
Total time: 53 min
Cuisine: American
Ingredients: 5 tablespoons unsalted butter (divided); 1 tablespoon olive oil; 3 cups mirepoix (or use 1 cup diced carrots, 1 cup diced celery, and 1 cup diced yellow onion); 2 teaspoons minced garlic; 1-1/2 pounds baby gold or red potatoes (diced (4 cups)); 1-1/2 teaspoons Italian seasoning; 3/4 teaspoon salt; 3/4 teaspoon pepper; 3 cups chicken stock (or broth, see note 1); 2 cups frozen broccoli florets (thawed and finely chopped); 1 cup frozen corn; 6 tablespoons flour; 3 cups whole milk; 1/2 cup heavy cream; 2 cups shredded sharp Cheddar cheese; Hearty, buttered bread (optional, for serving); Fresh herbs (optional, for serving (parsley or thyme))