Caramelized onions are a great “secret” ingredient to have on hand. They lend their rich flavor to Twice-Baked Potatoes with Caramelized Onions and Blue Cheese and Rice and Lentils with Ham. But they also add depth and sweetness to stews, risottos, sandwiches, burgers and more. The secret to making them is patience. It can take up to 40 minutes for the onions to become deeply browned, but the result is worth every minute. Covering the skillet at the beginning helps the onions to soften and release their liquid, then slowly cooking them uncovered makes them meltingly soft and sweet. Since caramelized onions will keep covered and refrigerated for a week and can even be frozen, you may want to make a big batch for an instant source of flavor to enhance weekday meals.

The recipe: Caramelized Onions