If I have signature recipe, this is it.  I found it years ago through a copycat recipe website, but I've made some tweaks here and there and this is the version my family (minus Molly) loves. 
It's perfect for a cold, rainy, cloudy, snowy days and evenings.  We've added it to our Christmas Eve menu.  Just as with most soups, it's much, much better the next day!   Just refrigerate overnight and reheat.

Note: this pic has some onion halves floating in it b/c Jamie does not, will not eat any food item that contains a piece of an onion, yet he likes a little onion flavor.  So, I just add a couple of onion halves while it simmers.

It's not a quick recipe.  You sort of need to plan to make this and give it time to simmer through the afternoon or maybe transfer it to a Crock-Pot.  I have tried freezing it -- don't.  If you gals who requested this make it, let me know how you like it.  This recipe is halved and it makes plenty!  You can double it for large crowds, but you are going to need a BIG pot.

"Chili's" Chicken Enchilada Soup

1/4 c. vegetable oil
1/2 c. chicken base (use the broth from when you boil the chicken breast)
2 tsp. ground cumin
2 tsp. chili powder
2 tsp. garlic salt or powder
1/2 tsp. cayenne pepper (I just use black pepper and quite a bit more than this)
1 c. Masa Harina (corn flour found in the Hispanic foods)
2 qts. water (divided)
1 1/2 c. crushed tomatoes
1 can Ro-Tel (optional)
1/4 lb. Velveeta
1 1/2 lb. cooked chicken (I boil mine, then "shred" it)

Shredded Colby-Jack cheese
Tortilla chips

In large pot, place oil, chicken base, and spices.

In another container, combine Masa Harina with 2 c. water.  Stir until all lumps are dissolved.  Add to pot and bring to boil.

Once mix bubbles, continue cooking 2-3 minutes, stirring constantly.  This will eliminate any raw taste from the Masa Harina.  (You will think this doesn't look like it could ever be soup b/c it will be very thick).

Add remaining 6 c. of water to pot.

Add tomatoes and Ro-Tel; let mixture return to a boil, stirring occasionally.  (You will have some lumps that form from the corn flour.  I usually try to mash those out).

Add cheese to soup.   Cook, stirring occasionally until cheese melts.

Add chicken; heat through.

Serve in bowls, top with shredded Colby-Jack cheese and crushed tortilla chips.