Layer half of sliced onion on the bottom of your crock pot. Cut roast into 3-4 large pieces and add to crock pot then sprinkle with salt and pepper. Add half head of garlic (no need to remove paper wrap), the rest of the onion slices, chicken stock, bay leaves, jalapenos, lime juice and lime halves plus oregano and Rotel tomatoes.
**NOTE Some people have experienced a bitter taste because of the lime juice. You can make this optional and add at the end of cooking as a flavoring.
Cover and set to high and cook for 4- 4 1/2 hours or until meat is tender and pulls apart like butter.
Remove meat from the crockpot and set aside to cool enough to handle and shred pork. Remove lime rinds and bay leaves and discard. Remove jalapeno slices and chop finely. Remove garlic, discard paper casings and chop finely and add jalapeno and garlic back to the crockpot with half of the pork, carrots and hominy. Cover and cook for an additional half hour or until warmed through and carrots are fork tender.
Reserve the other half of the pork for sandwiches, burritos or chili.