Ingredients

The following ingredients have 4 Servings
  • 5 tbsp extra-virgin olive oil (divided)
  • 6 boiler onions (about 1 cup, or pearl onions)
  • 8 oz mushrooms (white button, stems trimmed)
  • ½ Kosher salt
  • ¼ black pepper (freshly ground)
  • ½ cup balsamic vinegar
  • 1½ tbsp sugar
  • 1 lb haddock (cut into 4 individual fillets)
  • 6 sprigs thyme (fresh, plus more for garnish, chopped)

Instruction

  • Heat oven to 400°F.
  • Bring 2 cups of water in a medium pan to a boil over high heat. Add the onions and cook for 1 minute. Drain. When cool enough to handle, use a knife to snip off the ends of the onions. Use your fingers to gently squeeze the onion out of the skin. Set aside.
  • Heat 3 tablespoons of oil in a large saucepan/skillet over medium-high heat. Add onions and mushrooms and a good pinch of salt and pepper and sauté, stirring occasionally, until nicely browned and soft, about 10 to 12 minutes.
  • Add vinegar and sugar to the skillet and simmer. Stir frequently with a wooden spoon to scrape any browned bits stuck to the bottom of the skillet. Cook until sauce thickens slightly and comes almost like syrup, just a few minutes.
  • Rub haddock fillets with the remaining 2 tablespoons of oil, then season with salt and pepper. In a non-stick skillet, heat a little oil over medium heat.
  • When the skillet is hot, add fillets, skin side up, and sear until lightly browned on the bottom, about 4 minutes. Remove from heat and place the fish, seared side up, in a baking dish. Pour the mushroom agrodolce sauce all over the fish and top with the sprigs of thyme.
  • Place in oven and roast until fish is cooked through, about 10 minutes. Remove from oven and discard the thyme sprigs on top. Plate and garnish with a pinch of chopped fresh thyme. Serve at once.