Preheat an oven to 325°F and set oven racks in the top and bottom thirds of the oven. Season ribs generously with salt and pepper. Tightly wrap each rack of ribs in 2 layers of foil. Divide foil-wrapped ribs between 2 baking sheets and bake until tender (about 2 hours). Halfway through cooking, switch the positions of the baking sheets to ensure even cooking.

While the ribs are cooking in the oven, prepare the glaze. Bring Coca-Cola® to a boil in a medium saucepan set over high heat. Continue to boil on high until the coke is reduced to about 1 cup (45 to 50 minutes). Add kimchi juice, brown sugar, mustard, miso, fish sauce and vinegar, stirring to combine. Bring the mixture back to a boil, reduce heat to medium and simmer until reduced to 2 to 2 1/2 cups (30 to 35 minutes).

Let the ribs cool in the foil for a few moments, then drain off any excess fat and liquid. Cut each rib rack into 2 bone pieces. Reserve 1 cup of glaze for serving, then brush the remaining glaze all over the ribs. Grill or broil ribs, turning occasionally, until glazed and blackened in spots (about 5 minutes).

To serve, place ribs on a large platter with lime wedges and small mounds of kimchi. Top with a scattering of sliced scallion greens and enjoy immediately!