(Best of VT)
Heat oil in a large (4-quart) saucepan and sauté the onions until translucent. Stir in garlic. Add beans, water or bean-cooking liquid, chili powder, cayenne, prepared mustard, and cumin. Bring mixture to a boil over medium-high heat. Cover and reduce heat and simmer until beans are very soft, about 10-15 minutes. Stir in soy sauce or miso.
Mash the beans in the pot with a potato masher or large slotted spoon. (If you're using a nice, coated pan transfer the beans to a mixing bowl to mash them and return to pot.) Simmer mashed mixture, uncovered, over medium-low heat to cook away any excess liquid, about 25 minutes. Taste and add more seasoning if desired.
Preheat oven to 375°. Spread about 2/3 cup bean mixture down the middle of each tortilla. Spread about 1/2 cup mashed sweet potato on top of that. (I mix the mashed sweet potato and the bean mixture together in the pot, but this way looks a little more aesthetically pleasing.) Sprinkle with some green onions and roll the burrito, folding the sides over the filling in the middle. Place the burritos seam down onto a lightly greased baking pan (I prefer one with high sides.) Bake 10-15 minutes or until burritos are crisp. Ply with toppings and garnishes of your choice and enjoy.
8 servings at 9 POINTS per serving: 494 calories, 5g total fat, 15g dietary fiber