Pork Ribs with Black Garlic Miso Glaze

• 1 slab baby back pork ribs (about 2 pounds)
• 2 teaspoons fine sea salt
• 1/2 teaspoon black pepper, plus more to taste
• 2 cups water
• 2/3 cup dry white wine
• 1/3 cup black garlic cloves
• 3 small unpeeled shallots (about 4 1/2 ounces)
• 3 dried shiitake mushrooms (about 1/8 ounce)
• 12 thyme sprigs
• 3/4 cup red miso
• 1/3 cup honey
• 1/4 cup sherry vinegar (such as Sanchez Romate Reserva)
• 2 tablespoons vegetable oil

Sliced scallions, for garnish

1. Sprinkle rib slab with salt and pepper; place on a baking sheet lined with aluminum foil, and refrigerate, covered, 12 hours. Remove ribs, and let stand at room temperature 1 hour.
2. Preheat oven to 300°F. Place ribs in a large roasting pan. Add 2 cups water, wine, black garlic cloves, unpeeled shallots, mushrooms, and thyme sprigs. Place a sheet of parchment paper over ribs, and cover pan tightly with aluminum foil.
3. Roast ribs in preheated oven, covered, until meat is tender when pierced with the tip of a knife, about 2 hours and 30 minutes. Transfer to a cutting board, and let cool completely, about 30 minutes.
4. While ribs cool, remove garlic cloves and shallots from liquid in roasting pan, and set aside. Pour liquid through a fine wire-mesh strainer into a bowl. Skim off as much fat as possible. Set liquid aside, and discard solids.
5. Peel reserved shallots, and place in a blender. Add reserved garlic, reserved liquid, miso, honey, and sherry vinegar. Process until smooth, about 1 minute. Transfer miso mixture to a small saucepan, and bring to a boil over medium. Reduce heat to medium-low, and simmer, stirring often, until mixture is reduced to a thick barbecue sauce–like consistency, 20 to 25 minutes. Remove from heat, and let black garlic miso cool slightly, about 15 minutes.
6. Meanwhile, cut rib slab into individual ribs. Heat oil in a large cast-iron skillet over medium until oil begins to shimmer. Working in 2 batches, cook ribs on each cut side until deep golden brown, about 2 minutes per side. Flip ribs, rounded meaty side down, and cook until deep golden brown, about 1 minute. Transfer to a platter, and immediately brush hot ribs with black garlic miso. Garnish with scallions, and serve with additional black garlic miso.