Preheat oven to 425 degrees F and grease a 13×9 pan.
Heat oil in a skillet on medium heat. Mince garlic and chop sweet potatoes into small pieces.
Cook garlic and sweet potatoes in covered pan for 15 minutes. Stir every few minutes.
Once sweet potatoes are tender, add black beans and spinach to pan. Mix ingredients together until spinach is cooked.
Place 5 tortillas in bottom of 13×9 pan. You may need to halve them and arrange to completely cover the pan. Pour 1/3 of the enchilada sauce over tortillas. Spoon out half of the sweet potato mixture. Cover with 1 cup of cheese.
Repeat above step.
Layer last 5 tortillas and cover with remaining enchilada sauce and cheese.
Bake in oven for 25-30 minutes, until cheese on top has reached desired goldenness 🙂