Slow cooked onions are good enough by themselves, but when you combine them with the liquid exuded by olives and tomatoes you have a gloriously juicy bed on which to serve any fish fillet or steak. This combination, I think, is best with grilled tuna or swordfish—their meatiness gives them the presence to stand up to the richly flavored mass of onions, creating an easy dish that is strikingly Provençal and perfect for summer.

　　

Ingredients

makes 4 servings

　　3 tablespoons extra virgin olive oil

　　3 large or 4 or 5 medium onions, thinly sliced

　　Salt and freshly ground black pepper

　　1 large fresh thyme sprig or a large pinch of dried

　　2 medium tomatoes

　　1 1/2 to 2 pounds tuna or swordfish

　　About 1/2 cup pitted and roughly chopped black olives

　　

Step 1

Put the olive oil in a 10- or 12-inch skillet over medium heat. Add the onions, a healthy pinch of salt, some pepper, and the thyme. Cook, stirring occasionally, until the mixture starts to sizzle, a minute or two. Adjust the heat so that you have to stir only every 5 minutes at most to keep the onions from browning. They will become progressively softer; do not allow them to brown. Figure at least 30 minutes total for the onions to cook.

　　

Step 2

Core the tomatoes, then cut them in half horizontally. Squeeze and shake out the seeds, then cut the tomatoes into 1/2-inch dice. Preheat a grill to moderately hot.

　　

Step 3

When the onions are very soft, almost a shapeless mass, season the fish and grill it, turning once, for a total of about 6 minutes for tuna, 8 to 10 minutes for swordfish; check for doneness by making a small cut in the center of the fish and peeking inside. (Tuna can be quite rare; swordfish is best cooked to medium, when its interior is still slightly pearly rather than completely opaque.) While the fish is grilling, stir the olives and tomatoes into the onions and raise the heat a bit; cook, stirring occasionally, until the tomatoes liquefy and the mixture becomes juicy. Taste and adjust the seasoning. Serve the fish on a bed of the onion confit.

　　

Variations

Step 4

Chicken with Onion Confit: Serve the onions with grilled skinless, boneless chicken breasts.

　　

Step 5

Omit the thyme and use a bay leaf instead, or finish the dish with a handful of chopped fresh basil, chervil, or parsley.

　　

Step 6

Cook some finely chopped aromatic vegetables, like carrots, celery or fennel, and garlic, along with the onions.

　　From Mark Bittman's Quick and Easy Recipes From the New York Times by Mark Bittman Copyright (c) 2007 by Mark Bittman Published by Broadway Books.Mark Bittman is the author of the blockbuster Best Recipes in the World (Broadway, 2005) and the classic bestseller How to Cook Everything, which has sold more than one million copies. He is also the coauthor, with Jean-Georges Vongerichten, of Simple to Spectacular and Jean-Georges: Cooking at Home with a Four-Star Chef. Mr. Bittman is a prolific writer, makes frequent appearances on radio and television, and is the host of The Best Recipes in the World, a 13-part series on public television. He lives in New York and Connecticut.