Shallots are alliums, in the same family as white, red, and yellow onions, along with leeks, scallions, and garlic. That means they have that flavor that somehow borders on sweet, acidic, spicy, and sharp all at the same time. But the flavor of a shallot differs from that of a regular old onion in a few very important ways. The flavor of a shallot is more delicate, softer, and less abrasive than that of an onion. But the flavor is also a bit deeper, bringing in notes of garlic, which a white or red onion definitely doesn’t have.