Shallot: Shallots are one of the most powerful onions in the cook’s pantry because they’re mild, sweet, and flavorful in a way that other onions aren't. This sweetness is especially valuable in sauces, in which they can be used either cooked, in hot sauces, or raw, in vinaigrettes and mayonnaises, though raw shallot should be used judiciously. Their harsher effects can be eliminated by macerating them in vinegar; raw shallots are volatile so they should be cut and incorporated into the food the day you’re serving it (that is, don’t add them to a vinaigrette that will sit for several days in the refrigerator). They are also wonderful sautéed and used as a garnish, deep fried, roasted whole, and glazed.
Of the many items that are ubiquitous in professional kitchens and not so in home kitchens is the shallot. Why they aren't ubiquitous at home, I don't know. They take an ordinary sauce and make it extraordinary. Saute mushrooms in a pan hot enough to brown them, add salt and pepper and they're fine. But add a spoonful of minced shallot and they become delicious. A vinaigrette is transformed by shallot. Add them to minced salmon and they transform the tartare. Or to an omelet. To understand their power, try adding finely minced shallot to mayonnaise with a little lemon juice. You'll have a delicious sauce for crudite, an artichoke or cooked cauliflower. Make the mayo yourself and you'll have a restaurant caliber sauce. One of my favorite garnishes for a stew is whole roasted shallot--wrap them in foil with a few drops of olive oil, salt and pepper, and roast them till they're tender. So easy, yet so powerful. (Still working on unsquishing Donna's good work.)