Dave Arnold developed a couple of interesting ISI techniques. Rapid infusion is probably the most useful. Here he is on the ISI YouTube channel demonstrating the technique. (Check out that channel for a bunch of recipes and ideas).
The other technique Dave Arnold developed mimics the result of vacuum infusion or quick-pickling using a chamber vacuum machine. You basically pop your soft ingredient in a bag with a flavorful liquid or booze or whatever, get all the air out, put the zippie in the ISI along with some water, and pressurize it to drive the liquid into the product.
A similar technique is rapid marination which uses pressure to drive marinades into soft product. Scallops in your whipping siphon? Why not?
ChefSteps has a siphon class with a bunch of techniques. It's paywalled, but they have a few public recipes that are worth checking out. Like their hollandaise. It's nice because you can make it a couple hours ahead and then hot hold it in the ISI in a circulator.
They also have a good tempura fry batter that's light and airy and doesn't require vodka or beer. That recipe was posted in a video to their FB page.
If you have access to liquid nitrogen, frozen and par-frozen foams are fun. The most famous dishes in that regard are probably the frozen apertifs at The Fat Duck and the frozen foam in Alinea's "dessert on the table" preparations. ChefSteps has a Fat Ducky recipe for Strawberries and Cream Cryocycles:
Microwave sponge cakes are another fun thing to do when you're not cooking for a crowd. Iron Chef Cat Cora was especially fond of using the ol' siphon cake technique in Kitchen Stadium to pull off a quick and convenient dessert. I have been meaning to do this myself, but it requires you to buy microwavable paper cups that I never seem to have on hand.
They also have an ISI kimchi recipe if you like yours bubblin' for some reason. And there's rapid nitro cold brew coffee, if you're in a hurry. These are basically just applications of rapid infusion.
Lots of fun possibilities. Mine mostly makes whipped cream.
