Brown ground beef in medium skillet over medium heat, stirring to crumble. Drain off excess fat.
1 pound ground beef
Add taco seasoning and 1/3 cup water to the pan with the cooked ground beef. Stir well and cook for 2-3 minutes. Stir in black beans. Remove from heat.
1 packet taco seasoning, 1/3 cup water, 1 cup black beans
Spoon a small amount (about 1-2 Tbsp) of enchilada into bottom of square baking dish. Spread into thin layer. Top with four slices of zucchini.
1/2 cup enchilada sauce, 3 zucchini
Divide half of ground beef mixture and spoon on top of zucchini. Top with 1/3 of remaining enchilada sauce. Repeat. Top last layer of zucchini with enchilada sauce. Cover with foil and bake for 15 minutes.
Remove from oven and discard foil. Sprinkle with cheese and chopped cilantro.