Mash garlic and mix with salt; mix with honey, soy sauce, chicken broth, and ketchup or tomato puree. Pour mixture over the ribs, refrigerate, and let marinate for several hours or overnight. Turn several times to coat all surfaces.
Preheat oven to 450°. Put spareribs in the roasting pan with marinade. Bake 10 minutes. Reduce oven temperature to 325°. Bake for 1 hour and 20 minutes longer, or until ribs are tender. Baste occasionally.
Put ribs on a serving platter and keep warm in the oven while you thicken sauce; add enough water to the liquid in roasting pan to make 1 cup. Make a paste with the cornstarch and a small amount of water, then blend into the liquid , cooking until thickened and clear. Serve with the spareribs.
Serves 4.