Healthy Grilled Sweet Potato Nachos recipes

Name: Healthy Grilled Sweet Potato Nachos recipes
Ingredients: 2 large sweet potatoes; 1 tablespoon olive oil; 1 teaspoon each chili powder and cumin; 1 14-ounce can refried black beans (I like Amy's Organic brand); 1 cup frozen sweet corn; 3 oz. multigrain tortilla chips (enough for a single layer); chopped cilantro; cotija; ½ teaspoon butter; 1 large clove garlic, minced; 1½ cups milk; 2 tablespoons flour; ¼ teaspoon salt - more to taste; ½ cup shredded cheese of choice (I used Monterrey Jack)