Place ribs, soy sauce, brown sugar, garlic, ginger, pepper and 1 quart water in a roasting pan, cover with foil and roast for 4 hours. Remove foil and pour off excess liquid, then chill thoroughly.
For the sauce: Combine guava, soy sauce, honey, yuzu lime juice and salt and pepper in a saucepot and bring to a simmer on high heat. Combine cornstarch and enough water to make a slurry in a small bowl, then add to sauce while simmering. Cook at medium-high heat for 2 more minutes, then remove from heat.
Preheat a grill for cooking at medium-high heat.
Slice ribs into 2-rib portions, then grill 1 to 2 minutes on each side. Remove and place in saucepot with simmering sauce and simmer until hot, about 5 minutes.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.