According to Wikipedia, lemon chiffon cake is very light, moist cake. I remember it from childhood; the light weight of the dessert, its sweetness tempered by the tartness of lemon. In the same Really Delicious category as sabayon.
This morning I was in a cleaning out the fridge mood. Some canned pineapple chunks, leftover from previous pizza nights, needed to be eaten soon, as did the rest of the lemon yogurt. (Liberte Mediterranee brand - fantastically delicious).
My friend who works for a tofu company had just dropped off a sample of sweetened unflavoured soy milk. I usually buy the flavoured, hate the unsweetened, and had not tried the sweetened but unflavoured. It's terrific - a very good flavour by itself, yet neutral enough to use in shakes and smoothies.
So I blended those three ingredients in my magic bullet (which is really no different than my old blender, yet used way more often due to its size - kids can lift it - and flexibility of components).
Since I appreciate the power of marketing, I added bendy straws and called it Lemon Shiffon Shakes. Sounds so much better than "Using Up Old Food Shakes". The kids finished it, had seconds, and were sad to learn there was no more. Scarcity adds to deliciousness :)