In a 10-inch skillet, heat oil over medium heat. Soften tortillas one at a time in the oil for 15 to 20 seconds each. Transfer to a paper towel-lined plate. Remove pan from heat.
In a separate 8-inch skillet, heat olive oil over medium-high heat. Add zucchini, cumin, salt, and pepper. Cook, stirring often, for 5 minutes until tender.
Transfer zucchini to a bowl. Stir in black beans and 1/4 cup of salsa.
Spread 2 tablespoons of salsa in the bottom of a 5x5-inch baking dish. Place 1 tortilla on top. Add half the zucchini mixture and sprinkle with 2 tablespoons of cheese.
Top with another tortilla. Add the remaining zucchini mixture and 2 more tablespoons of cheese.
Add the final tortilla. Pour remaining salsa on top and sprinkle with the rest of the cheese.
Cover and bake for 15 minutes.
Uncover and bake for 5 more minutes, until the cheese is melted.
Notes
Make Ahead: Assemble the enchiladas, cover, and refrigerate before baking. When ready, bake as directed.
Baking Dish Size: Use a small baking dish (about 5x5 inches or similar) so the layers fit snugly and heat evenly.