If using the meat for burritos: shred the meat and add it to a frying pan with 1 cup of the cooking liquid. Simmer until the sauce has thickened, about 15 minutes.
To freeze the meat, transfer it to a freezer-proof container and add reserved 2 cups of cooking liquid. Freeze up to 6 months; thaw in refrigerator or microwave.
This recipe also works for pork and chicken. If you're using chicken, remove the skin before cooking and reduce the cooking time to 4 hours on High or 8 hours on Low. Remove the bones and shred the meat after cooking.