Preheat oven to 350℉.
In a small skillet, heat 1 tbsp vegetable oil over low heat, then add the chopped onions. Sauté until soft, then remove from the heat and set aside.
In a separate medium skillet, warm up the Texas Enchilada Sauce (made in advance).
Heat 1 cup vegetable oil in a heavy skillet to 350℉. Using tongs, carefully dip corn tortillas in the hot oil for about 5 seconds, until limp. Place on paper towels to drain.
After all tortillas have been dipped and drained, dip them in enchilada sauce to coat, then stack them on a baking sheet.
Remove each sauced tortilla, add 2 tbsp grated cheese and 1 tbsp chopped onion. Roll them up and place them side by side in a casserole dish.
Ladle the remaining sauce over the enchiladas, and top with the remaining cheese.
Bake at 350℉ for 15 minutes. Garnish with cilantro and serve hot.