For the sauce:

One 15 ounce can of tomato sauce

1 and 3/4 cups vegetable broth

1 teaspoon chili powder

1 teaspoon garlic powder

1 teaspoon onion powder

1 teaspoon oregano

1 teaspoon chipotle chili powder

For the filling:

1 tablespoon extra-virgin olive oil

1 onion, chopped

3 cups sweet potatoes, skinned and chopped (about 2 large sweet potatoes)

One 15-ounce can fire-roasted diced tomatoes, drained

One 16-ounce container prepared salsa

2 garlic cloves, minced

1/2 cup water

One 15-ounce can black beans, drained and rinsed

1 and 1/2 cups frozen corn, thawed

Daiya cheese or Teese

16 6-inch corn tortillas

Avocados, sour cream (or Greek yogurt), black olives, limes, etc