This onion relish is a kitchen treasure to keep on hand in the refrigerator. It can be used so many ways—tossed with vegetables, as a topping for meats or burgers, stirred into whole grains, or folded into soups. It’s especially delicious paired with roasted or grilled peppers, and also makes a flavorful base for pastas and sandwiches.
The first time you make this, take your time and pay attention to the process. Once you’ve done it a couple of times, you can start experimenting—try using higher heat for faster cooking, varying the thickness of the onion slices for different textures, swapping in other onion varieties or vinegars, or adding herbs. I often make this relish while working on other kitchen tasks like preparing tapenade, Romesco sauce, or salad greens.
INGREDIENTS:
3 large brown onions, peeled and thinly sliced into 1/8 inc crescents
2 tablespoons olive oil
1-2 tablespoons good quality balsamic vinegar
1 smallish pinch salt
Water as needed
METHOD:
Heat a heavy-bottomed saucepan over medium-high heat. Add the olive oil, and when it shimmers, add half of the onions. Stir to coat in the oil.
Once the onions have softened slightly, add the remaining onions and stir well. Continue cooking, stirring often to prevent burning and ensure even cooking.
When the onions begin to reduce in volume and turn golden, lower the heat to its lowest setting. Cook slowly until the onions are very soft, sweet, and golden brown. If they start to stick or scorch, add about 2 ounces of water to loosen them.
Stir in the balsamic vinegar and a pinch of salt. Cook until the liquid reduces to a syrupy glaze and the onions are deeply caramelized.
Remove from the heat and transfer to a bowl or jar to cool. Store in the refrigerator for up to 1 week, or use immediately.
CHEF NOTES: Once you’re comfortable with the process, you can speed things up: cook the onions over slightly higher heat, adding a splash of water and covering the pan with a tight-fitting lid. The steam helps soften the onions faster. Check frequently to prevent scorching. Once the onions are fully wilted, remove the lid and sauté until golden. Finish with balsamic vinegar as above. Using water strategically lets you make this relish more quickly without sacrificing flavor.
YIELD: 1-1½ cups of caramelized onions.
SOURCE: Chef Andrew Cohen
