Saute onion, zucchini, peppers, garlic and salt until onions get brown and caramelized. About 10 minutes.
Add cilantro and saute 1-2 more minutes.
Add black beans and juice, enchilada sauce and sour cream. Heat until thickened. About 3-4 minutes. Remove from heat.
Place about ¾ cup of the enchilada sauce at the bottom of a baking dish, covering it with a thin layer.
Build enchiladas by placing a few spoonfuls of filling in the middle of each tortilla. Next roll the tortilla and place seam side down in baking dish. Repeat until all tortillas are used.
Cover the rolled tortillas with the remainder of the enchilada sauce. Then drizzle with the sour cream.
Then, cover with your sliced green onions and chopped cilantro. Add sliced limes if preferred.
Bake at 350 degrees for 20-25 minutes until the sauce is nice and bubbly.
Notes
You can use any leftover veggies you have, just make sure it equals a total of 3 cups.
The juice of the black beans help thicken the filling, feel free to omit if you want and rinse and drain them instead.