Chicken Enchiladas with Red Chili Sauce

I can't remember where I found this recipe, but it's been stuck to my fridge (where I keep all new recipes until I try them) for a month or two. It's a good go-to recipe since most of the ingredients are found in my pantry on any given day. I tweaked the recipe so that it wouldn't be too spicy for my little lady.

Chicken Enchiladas with Red Chili Sauce
1 tsp vegetable oil
1 onion, chopped
salt and pepper
3 cloves garlic, minced
3 tablespoons chili powder
1 tablespoon cumin
2 tsp sugar
1 15-oz can tomato sauce
1 lb boneless chicken breasts, sliced thin
2 cups shredded cheddar cheese
3 tablespoons chopped pickled jalapenos (I omitted)
1/2 cup minced fresh cilantro (I omitted)
Preheat oven to 425 degrees. Grease a 9x13 pan. Warm oil in a pan over medium heat. Saute onion and salt for 8 minutes. Stir in garlic, spices and sugar. Add sauce and 1 cup water. Reduce heat and simmer for five minutes.
In a separate pan, cook chicken until cooked through. Season with salt and pepper. In a bowl, combine chicken and 1/4 cup sauce mixture (can also add jalapenos and cilantro in this step). Spoon 1/3 cup onto each tortilla and sprinkle with cheddar cheese. Roll up and lay seam-side down in baking dish. Mist with cooking spray.
Bake, uncovered, for 7 minutes. Reduce temperature to 400. Pour sauce over enchiladas and top with remaining cheese. Cover with foil and bake 25 minutes. Uncover and bake 5 minutes more.