- Cook rice according to package directions, omitting salt and adding 1 Tbsp. soy sauce to water.
- Remove skins and slice 1/2 inch from top of each onion. Scoop out centers of onions leaving 1/2-inch shell, about 3 rings. (A grapefruit knife is handy for this.) Chop enough onion centers to make 1/3 cup. Refrigerate or freeze remaining centers to use as fresh onions.
- Heat 1 Tbsp. oil in skillet over medium-high heat. Add egg and scramble; remove from pan.
- Heat remaining oil in same skillet. Add chopped onion, celery, garlic and ginger; stir-fry 1 minute. Add cooked rice, egg, peas and remaining 1 Tbsp. soy sauce; stir-fry 1 minute longer. Remove from heat and spoon into onion shells. (Onions may be covered and refrigerated at this point.)
- Place 1 cup water and cooking rack in 4 or 6-quart pressure cooker. Place onions on rack; close securely. Place pressure regulator on vent pipe. Heat pressure cooker over high heat until regulator begins to rock. Adjust heat to maintain slow steady rocking motion. Cook at 15 pounds pressure for 9 minutes. Cool pressure cooker at once.