Preheat oven to 425°F (220°C).
Toss sweet potatoes with 1 tablespoon olive oil and roast for 20 minutes until tender.
Heat remaining oil in a large skillet over medium heat.
Add onion and bell pepper, cook until softened, about 5 minutes.
Add garlic and spices, cook for 1 minute.
Add black beans and roasted sweet potatoes, mash slightly.
Warm tortillas and fill with bean mixture.
Roll and place seam-side down in a baking dish.
Top with enchilada sauce and cheese.
Bake for 15 minutes until heated through and cheese melts.
Garnish with cilantro and avocado, serve with lime wedges.