Growing up, I thought that garnish was green frilly stuff. It was the anemic lettuce leaf under the crab salad, the parsley nestled between the steak and potato, the mint shoved into the whipped cream on top of the chocolate cake.
My definition stayed narrow until I met Monsieur Escoffier. Okay, I didn't actually meet him, being that he's all Dead and stuff, but I met his work. And what I realized was this: when he used the term garnish, it pretty much meant everything on the plate that wasn't the protein. So, a stew could be garnished with tourneed vegetables, sauces, a small salad, a puree, etc.
I was raised thinking that a garnish was a throw-away. No need to eat that parsley or that piece of lettuce. After meeting Escoffier, I began to think of the garnish as components that harmonize with the Main Event--not at all throw-away-able, but integral to the whole presentation.
One cool thing that comes from understanding the classical meaning of garnish is that you come to realize that the main event can be garnished in any number of ways, as long as the garnishes that you choose complement and harmonize with the main event.
Desserts can be served at four basic temperature ranges: frozen, chilled, room temperature and heated. Textures can be creamy, crunchy, crispy, chewy, dense, light and airy, silky, etc. A well plated and garnished dessert should contain elements from three temperature ranges and at least two complementary textures. For example, a "simple" piece of apple pie is generally served heated and with two basic textures--a fruity bite and a crisp/flaky pastry. Appropriate garnish could consist of frozen/creamy ice cream and/or crunchy/room temperature nut brittle and/or light and airy/chilled whipped cream. You probably intuitively do this anyway. Who doesn't like warm apple pie with ice cream or some whipped cream, right? Just do like mom used to do: elevate a bowl of sherbet from a one note frozen treat to a study in contrast of texture and temperature by sticking a couple of wafer cookies into it.
Make sure you consider the dish as a whole and take care that all the components make sense together. If the dessert doesn't have any mint flavor in it at all, just walk away from that leaf of mint you've been eying. If there's nary a berry in the dessert, put away that insipid strawberry fan. Likewise, if the only strawberries you can find in the middle of December are white and green, that is nature's way of telling you that they are Out of Season and it's best to just wait for the summer. Only a dish with orange notes in it requires that jaunty twisted orange slice, so just give it back to the bartender right now.
When you begin to conceptualize a dish, consider the texture and temperature of your main dessert and then design the garnishes accordingly.
Here are some examples to get your creative juices flowing:
1. Toasted pound cake (heated/toasty/cakey) with fresh berries (room temperature or chilled/juicy/fruity), lemon curd (chilled/silky) and a shard or two of caramelized sugar (room temperature/shattery).
2. The hot fudge sundae: frozen/creamy ice cream, heated/smooth/almost chewy fudge sauce, chilled/light and airy whipped cream, room temperature/crunchy nuts
3. Syrup-soaked genoise (cool/light/airy/cakey/moist) with Italian buttercream (*room temperature/light/smooth/creamy/poufy) and macaron shells (crisp/light/chewy) with a quenelle of sorbet (frozen/icy-smooth).
Now, none of this seems like rocket science, mainly because it isn't. It really is pretty intuitive, especially when you keep the temperature ranges and textures in mind. Of course, we haven't even touched upon harmonizing flavors. Stay tuned, as they say, for the rest of the story...
*If you take your cake out of the fridge 30-45 minutes before serving, the frosting on the outside will be room temperature while the inside is still cool. Very nice.