Although the cinnamon is unexpected, the mint turned out to be the nicest surprise here, elevating the onions and adding to the sweet-sour notes of the dish.
Grilled Tuna With Caramelized Onions, Cinnamon and Mint
4 tablespoons canola oil
2 large Spanish onions, cut in half, then into thin slices
1 tablespoon sugar
Pinch crushed red pepper flakes
2 3-inch cinnamon sticks
¼ cup red wine vinegar
Freshly ground black pepper
4 8-ounce tuna steaks
2 tablespoons finely chopped fresh mint leaves, or more to taste
Heat 2 tablespoons of the oil in a large saute pan over medium heat. Add the onions and sugar and cook until soft, about 10 minutes. Add the crushed red pepper flakes and cinnamon sticks; cook, stirring occasionally, for 30 minutes or until the onions are lightly golden brown and caramelized. Stir in the vinegar and a few tablespoons of water; season lightly with salt and pepper.
Prepare the grill for direct heat. If using a gas grill, preheat to high (475 to 500 degrees). If using a charcoal grill, light the charcoal or wood briquettes; when the briquettes are ready, distribute them on one side of the cooking area. For a very hot fire, you should be able to hold your hand about 6 inches above the coals for no more than 1 or 2 seconds. Have ready a spray water bottle for taming any flames. Lightly coat the grill rack with oil and place it on the grill.
Brush the tuna steaks on both sides with the remaining 2 tablespoons of oil. Season lightly all over with salt and pepper. Place on the grill and cook uncovered until golden brown and slightly charred, about 2 minutes per side (for medium-rare).
Transfer the tuna to a platter. Discard the cinnamon sticks from the onion relish and stir in the mint. Top the tuna with the relish. Let sit at room temperature for about 15 minutes; just before serving, stir in more mint, if desired. Serves 4.
Note: The onions can be cooked, cooled and refrigerated a few days in advance. Stir in the mint no more than 15 minutes before serving.
– Adapted from “Bobby Flay’s Barbecue Addiction” by Bobby Flay with Stephanie Banyas and Sally Jackson (Clarkson Potter, 2013).
Per serving: 420 calories, 54 g protein, 11 g carbohydrates, 16 g fat, 2 g saturated fat, 100 mg cholesterol, 150 mg sodium, 1 g dietary fiber, 6 g sugar.