Crock Pot Broccoli Cheddar Veggie Chowder

Name: Crock Pot Broccoli Cheddar Veggie Chowder
Ingredients: 18 ounces fresh broccoli florets (Dole); 2 stalks celery, chopped; 2 cups shredded carrots; 1 small onion, chopped; 1 tablespoon minced garlic; 4 tablespoons butter; 6 cups chicken broth; 6 cups water; 1 cup milk; 1 (10 3/4 ounce) can cheddar cheese soup; kosher salt; fresh ground black pepper; 16 ounces frozen southern style hash brown potatoes (cubes, not shredded); 2 cups shredded sharp cheddar cheese; 1 tablespoon cornstarch; 2 tablespoons cold water