In a 4-quart saucepan bring 3 quarts salted water to a boil for orzo.
In a heavy saucepan simmer bell peppers in wine and broth with salt, covered, until tender, about 15 minutes. Remove lid and simmer until liquid is evaporated. Cool pepper mixture and in a food processor or blender pur, e with egg substitute. Transfer pepper mixture to a large bowl.
Preheat oven to 350 ° F.
Cook orzo in boiling salted water until al dente and drain in a colander. Rinse orzo under cold water and drain well. Stir orzo into pepper mixture with scallions, chives, and salt and pepper to taste. Spread orzo in baking pan, smoothing top. Gratin may be prepared up to this point 8 hours ahead and chilled, covered.
Bake gratin in middle of oven 25 to 30 minutes, or until set and top is pale golden.
with the mixture and the other sprinkled on top before baking. As I can't get fat free parmesan here, I did without, but if you can get hold of it, it might make a nice addition.