Heat the oven to 200°C / 400°F. Lightly oil a medium baking dish, then spread about 1/2 cup of the enchilada sauce over the bottom.
Mix the chicken, onion, cumin, and about 1/2 cup of the enchilada sauce in a bowl.
Warm the tortillas briefly so they bend easily. Divide the chicken filling between them, roll tightly, and place seam-side down in the baking dish.
Pour the remaining sauce over the enchiladas and sprinkle with the shredded cheese.
Bake uncovered for 20 to 25 minutes, until the sauce is bubbling, the cheese is melted, and the filling is hot throughout.