Preheat oven to 400°F. Add the sweet potatoes, oil, and seasonings and garlic (if using) to a medium-sized bowl and stir to coat.
Spread the sweet potatoes across a large sheet pan and bake for 30-35 minutes, stirring halfway through. To crisp, broil the last minutes until browned.
Meanwhile, peel and slice or mince garlic, then rinse and drain two cans of beans. Heat a small saucepan over medium heat, then add garlic and cumin and saute for 30 seconds. Add ancho sauce/peppers and stir for another 30 seconds, then add the two cans beans, salt, and vegetable broth. Reduce to a simmer for 10 minutes, while stirring every so often. Remove from heat and stir with a fork until the desired mashed/whole bean consistancy is reached. Add lime and season to taste.
On the grill roast corn and husk or in a dry sauté pan over medium heat, add fire roasted corn and stir until cooked and set aside.
Scoop the flesh of two avocados into a bowl and smash lightly with a fork. Add cumin, salt, and lime, then mix again. Season to taste.
Taco Bite Assembly
Black beans on one side, then dot the sweet potatoes into the beans. Smashed avocado on the other side, then sprinkle roasted corn and red onion.Lettuce and cilantro through the middle, hot sauce everywhere.Fold, hold tight so the taco stays in form, and cut fast and in half with a serrated knife. Add a toothpick tight on opposing sides.