This is the recipe I have used for years.. it called for a crust but I have since made it without using the same basic formula. I can't remember if I had to adjust the baking time at all or not. Just keep an eye on it the first time you make it because ovens can vary anyway.
2 cups any combo of shredded cheese or veggies, or fruit
1 1/2 cups milk or other liquid
Saute veggies if using them. Sprinkle on bottom of pieshell. Beat the rest of the ingredients and pour over the sauteed veggies. PLace pie in a 450 degree oven. Reduce heat to 375 and bake about 35 minutes.
For my favorite combos I like artichokes/mushroom/a white cheese of some sort, Tomato/soy bacon/ cheddar, Broccoli/cheddar, Tomatoes/basil/olives and feta and spinach/cheddar The combinations are really only limited by your imagination!
I have never tried it but I would assume since fruit was listed you could add a little splenda, blueberries, vanilla extract, maybe ricotta for the cheese and use a vanilla protein shake for the liquid and make a nice fruity custard.
Ps... forgot to add, for dinners I sometimes add soy sausage/cheddar or soy burger crumbles/green chilies/cheddar to the quiche and serve the latter with sour cream, salsa, black olives and green onions on the side for everyone to sprinkle on top.