Lemon, parsley, and capers are a classic sauce used to flavor white fish. This recipe combines that sauce with heavy cream in a whipping siphon to create a light and airy mousse topping. The topping carries the flavors of the sauce while adding a delicate texture to the dish.
I often serve this mousse with seared or poached fish. When I do, I like to heat the plates in the oven before serving them, this not only keeps the fish hot but allows the mousse to begin melting as the dish is served.
The mousse also works well with cold fish preparations, such as smoked or cured salmon. It's a great twist on the classic lox and cream cheese. You can substitute any herbs and spices you'd prefer for your end dish, for example using chives or red onion in the cream for lox.
This recipe calls for using a whipping siphon, but you can also whip the cream using a mixer or whisk to get a similar texture. For a stronger flavor you can also briefly puree the cream mixture before straining.
The cream needs to cool off before it can be whipped. I usually do this in the whipping siphon in the refrigerator or an ice bath.
Note: You can learn more by viewing all my whipping siphon articles and recipes.
Measuring Note: Many home cooks are intimidated by using modernist ingredients because they are usually measured in grams. This recipe simplifies the process and uses regular volume measurements but I do recommend reading about how to measure modernist ingredients for a detailed look at why grams are more effective. This is especially important if you are going to scale a recipe up or down, or are working in a professional kitchen.