It’s very common to begin a recipe by sautéing onions. But are there any recipes where you instead simmer them in a liquid, to get a different flavour profile? I am picturing sautéing some shallots in cream and I’d like to know where this could lead forward to.
In some cases, you need to get the flavour to come out of its source and into the dish. Some flavours (flavour molecules) are soluble in water and others in fat, so different spices need different treatment.
Specifically with onions, they are a different case. We usually aren't only extracting the flavour from the onions but rather "releasing" and modifying it within the onions. The cooking changes the flavour.
An example of getting flavour out of products by cooking in water rather than oil is almost any soup. Onions in an onion soup, or any of the vegetables in a vegetable or chicken soup, and of course mushrooms in a mushroom or even miso soup are all examples of this.