Place tea bag in a small glass bowl. Pour boiling water over tea. Cover; let stand 5 minutes. Remove tea bag and discard. Meanwhile, tear off a 36x18-inch piece of heavy foil. Fold in half to make a double thickness of foil that measures 18x18 inches. Bring up all sides of foil to form a pouch. Place uncooked rice in center of pouch. Place margarine or butter on top of rice; sprinkle with salt. Carefully pour brewed tea over rice. Bring edges of foil together and seal tightly, forming a pouch, leaving space for steam to build. Grill foil pouch on the rack of an uncovered grill directly over medium-high coals about 25 minutes or until liquid is absorbed and rice is tender. Remove from grill. Carefully open packet. Add peas. Seal packet and let stand 10 minutes. Just before serving, sprinkle with fresh mint. Makes 4 servings.