Bring the chicken stock to a boil. Slice the pork into 5×5” chunks. Season with salt and pepper. Add the oil to a heated rondeau or brazier as needed. Sear the pork in batches on all sides until browned. Place the seared pork into 4″ stainless steel hotel pans.
Add the onions, carrots, garlic and bay leaves to rondeau. Cook until vegetables are browned and tender. Bring to a boil. Pour equal amounts of stock and vegetables between the two pans of pork. Cover pan tightly with foil. Place in a 300°F oven. Cook for 2½ to 3 hours or until spoon tender.
Pull the pork while it is still warm. Place in a covered storage container. Refrigerate until needed.
Strain the stock into a bain-marie. Allow to cool. Skim off any excess fat. Cover and refrigerate until needed.
To prepare à la carte:
Place the desired size portion of pork in a heated nonstick saute pan. Ladle the stock over the pork. Bring to a boil.Cook until the stock has reduced slightly.