Heat oil in a small skillet over medium-high heat, add onion and bell pepper and saute until they just begin to brown, remove from heat and set aside.
In a blender or food processor, combine the canned tomatoes, chipotle pepper, garlic, tomato paste and corn meal, blend or process on high speed until smooth and then pour the red sauce into a shallow mixing bowl that's at least six or seven inches in diameter.
In a medium sized mixing bowl, combine soup and sour cream.
Spread 1/2 of the soup and sour cream mixture over the bottom of a 9 x 13 inch baking dish coated with cooking spray.
Taking one corn tortilla, dip it into the red sauce to coat both sides, then place about one tbs. of the cheese and 1/3 cup of the chicken in the center of the tortilla, roll it up and place it in the bottom of the baking dish, continue until you have a single layer of enchiladas covering the bottom of the dish (I was able to fit in ten enchiladas, eight placed side by side vertically with two more placed horizontally at the top of the dish).
If you have any red sauce left over, pour it over the enchiladas, and distribute any remaining chicken over the top.
Spread the other 1/2 of the soup and sour cream mixture over the top of everything.
Sprinkle with the remaining cheese and the onion and bell pepper.
Bake in the center of the oven for 20-25 minutes until bubbly and heated through.