Brown the beef and turkey with the onions in a large skillet. Drain fat, then transfer cooked meat & onions to a large slow cooker (or stockpot). Add beans, corn, tomatoes, chiles, olives and seasonings; cook in slow cooker on low for 6 to 8 hours (or simmer on low heat for about 1 hour if using a pot on the stove).
To serve: sprinkle a few corn chips in the bottom of a bowl and ladle soup over them. Top with desired garnishes.
If you are counting WW Points, use all lean ground turkey instead of beef & turkey.
Fixings to serve with the soup (like corn chips) are not included in the nutritional information or WW Points.
This really isn't technically a "soup." It's more like a thick chili-sort of dish and it's fabulous over the corn chips- don't leave those out!
Add sliced, black olives if you'd like (optional).
Consider other garnishes too: guacamole, chopped onions, lettuce, tomatoes, etc.