Make up the beans like you would for a Mexican dish: spices, lime, etc. Cube and cook up the sweet potato separately.

Add the beans and sweet potato to the taco shell, put taco seasoning on top, put red salsa on top of that (to keep it moist), then wrap it up and top with a red sauce and whatever else.

I tend to like a sauce with adobo, but use whatever red sauce is your favorite!