3 racks of top-loin ribs (commonly called baby back ribs) 2lbs each
1 tablespoon kosher salt
1 1/2 teaspoons coarsely ground black pepper
1/2 cup dijon mustard
1/2 cup dark-brown sugar
1/4 cup cider vinegar
1/4 cup honey
4 garlic cloves, minced
1/4 teaspoon cayenne pepper (optional)
Turn on one side of a gas grill to medium-high heat. Cover and preheat until the thermometer registers 300 F.
Sprinkle the ribs evenly on both sides with salt and pepper. Place bone side down, as far from the flame as possible (you can also use a second-tier rack). Cover and cook until the meat pulls back slightly from the bones (1 1/4 to 1 1/2 hours).
Meanwhile, combine the remaining ingredients in a bowl and mix well.
When ribs are cooked, brush one side of a rib rack with the sauce, flip onto the flame, sauce side down, and cook until glazed, about 2 to 3 minutes. Repeat on other side.
Remove from the grill and repeat glazing with other rib racks.