Pour oil into crock pot or dutch oven and add meat.
Mix spices and sauces in bowl and pour over meat.
Cook slowly in dutch oven, and check meat for tenderness after 2 hours.
If added to crock pot instead, turn on low and let cook 6-8 hours.
In either case, re-move meat to serving plate and keep warm; bring sauce to a boil and stir frequently until thickened (about 5 minutes).
Skim fat from sauce, and serve with additional picante sauce over meat.