Make up the dry rub by whizzing the fennel seeds and garlic granules in a spice grinder or a pestle & mortar until they are powdered.
Mix with the rest of the ingredients in a large bowl.
Rub all over the rib racks and set in the fridge for 2 hours, overnight is ideal.
Place the rubbed racks on the grill and leave to cook on griddle until the meat starts to shred away from the bones when you insert a fork. Just make sure that the meat is falling off the bone when you serve them. If it isn’t, let them go for longer.
When they are ready, lightly brush the barbecue sauce over the ribs and place back on the grill for 15 minutes.
Remove from the heat and wrap in tin foil to rest another 15 minutes.
Serve warm with a little more barbecue sauce, if you want, and a cold Guinness Original.