Preheat oven to 350˚Heat oil on medium heat; add the onion and season with salt. Cook until the onion is soft (about 5 minutes) then add garlic, cumin and chili powder, chicken and 1 cup of the enchilada sauce, stirring until well combined. The remaining sauce will be used to top off the enchiladas.
Peel thin slices of zucchini. Lay out three sheets of zucchini, slightly overlapping, and place a spoonful of the chicken mixture on top. Roll up and transfer to the baking dish.
Repeat with the remaining zucchini and chicken mixture.
Spoon the remaining enchilada sauce over the enchiladas and sprinkle with both cheeses.
Bake for about 20 minutes or until the cheese golden and bubbling.