Slow Cooker Mexican Casserole- dump the ingredients in the crock pot for a easy and delicious meal! SixSistersStuff.com #crockpot #recipe. This was good. I did not cook it in the crock pot I just baked it in the oven at 400 for about 30 minutes. This made a large 9x13 pan. My husband did think it seemed more like a side or an appetizer.