Mix all marinade ingredients except pork shoulder in a large ziplock bag.
Trim as much surface fat from pork shoulder as possible. Cut pork shoulder into baseball size chunks to fit better in the ziplock bag and slow cooker. Place pork shoulder in marinade ziplock and refrigerate overnight. Turn ziplock bag occasionally to mix ingredients.
In the morning, pour entire contents of ziplock marinade bag into slow cooker. Cover and cook on low for 10 hours.
When the pork shoulder is done cooking, use 2 forks to lightly shred meat. It should be fork tender and shred easily.
Cut french roll lengthwise and then quartered into 8 sandwich rolls.
For each sandwich, liberally spread mustard on each half of the bread. Then place cheese, ham, pulled pork, pickled green beans and then another piece of cheese, in that order. Place top bun on to form sandwich.
If you have a panini press, use it to grill and press each sandwich for 2 minutes per side over medium heat, or until golden brown. If you do not have a sandwich press, use a buttered skillet and a tinfoil wrapped brick to apply weight.