Cornstarch is a functional, journeyman ingredient, neither sexy nor exciting. It does its job well; all you do to activate its thickening powers is mix it with a small amount of liquid to create a slurry you can stir into a hot soups, stews, pan sauces, puddings, or any liquid-y dish that needs a bit more body. Most people use water to create their slurry, but cool kids use booze.
Actually, I don’t know what the cool kids are doing. I haven’t been a kid, cool or otherwise, for quite some time. But replacing the water in your cornstarch slurry with brandy, sherry, rum, or wine allows you to sneak a bit more flavor into your recipe. If you are in the habit of avoiding alcohol entirely, you can use a concentrated stock, fruit juice, milk, or something that’s packed with umami, like soy sauce.
Making a slurry with fino sherry can add a bread-y, almond-y note to a fruit compote or vanilla pudding, and thickening a beef stew with a red wine slurry can add depth. Does your chili need more body and umami? Make a slurry with fish sauce. Neither will result in overwhelming flavor changes, but either will help you build layers of flavor in your dish.
Even better, you don’t have to make other adjustments to your recipe. Make the slurry the “normal” way, mixing equal volumes of liquid and starch together (two parts liquid with one part starch also works), whisking with a fork to break up any clumps. Drizzle the slurry into your dish while it’s hot—cornstarch works best at temperatures of 180℉ and up—then let everything simmer for a few minutes. Repeat as needed until your dish is thick and luscious. (Not sure if it’s “done”? Spoon a little onto a room-temperature plate and see how it behaves.)