BRINE: Combine salt, brown sugar, black peppercorns, hot red pepper flakes, bay leaves and hot water in a large bowl. Stir to dissolve sugar and salt. Add wine and ice water, stir to combine. Place ribs in a large, non-reactive baking dish. Pour brine over ribs, cover with plastic wrap and refrigerate 4-6 hours. Remove ribs from brine, rinse well under cold running water and pat dry with paper towels. (Brined ribs may be wrapped in plastic and refrigerated overnight.)
SPICE RUB: Heat a heavy, dry saucepan on medium high. Add coriander, mustard seeds and whole peppercorns and toast, shaking pan, until fragrant. Grind toasted spices in a spice grinder or small coffee grinder. Transfer to a small bowl and stir in salt, garlic powder, thyme, oregano and granulated sugar.
RIBS: Rub both sides of rib slabs with seasoning rub and let stand for 30 minutes at room temperature. Preheat a gas grill to medium high and lightly oil grill rack to prevent sticking. Place ribs on grill, meat side down, and grill covered for 10 minutes, checking frequently and reducing heat slightly to control excessive flame-ups. (A little bit of charring will give the ribs nice flavor but you don't want to blacken them completely). Turn ribs and grill covered until cooked through - about 10 minutes more. Serve immediately.