For the Baby Back Ribs:
Preheat the oven to 300°F. Season the racks of baby back ribs with salt, pepper, and mesquite, then put them on sheet trays. Bake for 2 hours, then remove them from the oven and allow them to cool. Preheat the vegetable oil in a deep casserole. When the ribs are cold, cut the individual ribs apart in order to bread them. Dip the ribs in egg whites, then in the bread crumbs. Deep fry all of the ribs until they are golden, then reserve them on a tray lined with paper towels to absorb excess oil.
For the Pickled Onions:
Cut the onions into rings. Combine some cold water with the red wine, vinegar, bay leaves, thyme, and sugar in a medium pot. Add the onions to the mixture, put the pot over a medium heat, and bring the mixture to a boil for 2 seconds. The onions are pickled when the pickling liquid is cold. Strain the onions.
To Assemble and Serve:
Plate the fried ribs and pickled onions with a small ramekin of BBQ sauce.