Cook the pasta until just becoming tender (about 5 minutes). Drain and set aside.
Mix the turkey, ketchup, and onion in a large bowl. Add the frozen cauliflower and cheese sauce, shredded cheddar, and pasta, and mix until distributed.
Place entire mixture into the crockpot and cook on high for 3-4 hours or on low for 8-9 hours.
When plating, sprinkle each serving with the chopped tomatoes and pickles, or set out in bowls for self-service.