Keep It Simple Salmon

Tried this super simple and tasty recipe for salmon last night. The touch of sugar balances the vinegar's acidity, and both offset the heartiness of the salmon. I'd recommend some simple fresh greens to offset the flavors; we ate this with sauteed fiddlehead ferns and shitake mushrooms, and a little bit of brown rice.

Salmon with Agrodolce Sauce

3 tablespoons olive oil, divided
4 (6-ounce) salmon fillets (1 inch thick) with skin
2 medium red onions (about 1 pound total), each cut into 8 wedges
2/3 cup balsamic vinegar
1 teaspoon sugar
1 tablespoon unsalted butter

Heat 1 tablespoon oil in a 12-inch nonstick skillet over medium heat until hot. Pat salmon dry and sprinkle with 1 teaspoon salt and 1/2 teaspoon pepper, then cook, skin side up, until undersides form a golden crust, 12 to 15 minutes. Turn fish over and cook until just cooked through, about 3 minutes more.

Meanwhile, heat remaining 2 tablespoons oil in a large skillet over medium-high heat until it shimmers, then sauté onions until golden brown and crisp-tender, 6 to 8 minutes. Stir in vinegar, sugar, and 1/2 teaspoon salt and cook until sauce is syrupy, about 2 minutes. Remove from heat and stir in butter.

Spoon onions with sauce onto plates and top with salmon, skin side down.