Puree all of the ingredients except the bay leaf, pork and buns in a blender until smooth.
Put the sauce, bay leaf, and pork into a large pot. Add 1 1/2 cups water. Cover the pot and bring to a boil. Simmer covered over the medium-low heat until the meat pulls apart easily with a fork (about 2-2.30 hours), stirring occasionally. Add more water during cooking, if necessary. Remove from heat and let stand until cool enough to handle. Then remove the pork from the sauce and shred into small pieces. Set the pork aside.
Put the sauce back on the stove and simmer over medium heat until sauce thickens. Add the pork back to the sauce, stir well. Taste and adjust seasonings.
Remove bay leaf and serve hot over sandwich buns.