In a medium saucepan, spray oil and sauté garlic. Add chipotle chiles, chili powder, cumin, chicken broth, tomato sauce, salt and pepper. Bring to a boil. Reduce the heat to low and simmer for 5-10 minutes. Set aside until ready to use.
Preheat oven to 400 degrees.
Heat the vegetable oil in a medium skillet over medium-high heat. Sauté onions and garlic on low until soft, about 2 minutes. Add chicken, salt, cilantro, cumin, oregano, chili powder, tomato sauce, chicken broth, and cook 4 to 5 minutes. Remove from heat.
Spray a 13 by 9-inch glass baking dish with non-stick spray. Put 1/3 cup chicken mixture into each tortilla and roll it.
Place on baking dish seam side down, top with sauce. Then top with cheese.
Cover with aluminum foil and bake in the oven on the middle rack for 20-25 minutes. Top with low fat sour cream or scallions if you wish. (Extra points) Makes 8 enchiladas.