Preheat oven to 400 degrees. Place the diced sweet potatoes (in half-inch chunks) on a parchment paper-lined baking sheet. Drizzle with 2 Tbsp. olive oil; salt and pepper. Bake for 25-30 minutes, until tender with a fork. Remove from the oven.
Turn oven down to 350 degrees. In a large skillet, add remaining 2 Tbsp. oil, chopped onion, and pepper, and saute for 5-6 minutes.
Stir in the green chilies, drained beans, and olives and cook for another 2-3 minutes.
Melt butter in a saucepan. Add flour, chili powder, and cumin. Cook until bubbly. Add tomato sauce and water. Bring to a boil.
Dip corn tortillas in sauce, then put in pan and fill with veggie mixture and cheese and roll up. Pour sauce on top and then more cheese. Bake for 20 minutes, until bubbly. Serve!
Garnish with sour cream and fresh chopped cilantro (maybe a few pieces of chopped red tomatoes). ENJOY!
Notes
Recipe updated with new photos and reposted from May 2017.