Saute the onions in the oil.
Drain the potatoes from the water and reserve the potato starch remaining at the bottom.
Add potatoes to the onion and oil, along with the starch, cook until translucent.
Spray a deep cookie sheet with release spray and place the potato mixture in it.
Bake at 350 F. until potatoes are crisp and golden brown.
Remove from oven and let cool.
Combine the egg substitute with the non fat half and half and season with the Salt & Pepper.
Pour the custard over the cooled potatoes and top with the grated soy cheese.
Stir the cheese into the custard and bake @ 350 F. for 20 min. or until the custard is set.