The haddock and cheddar mash at Dublin's The Winding Stair restaurant represents the best of Ireland: sea, dairy, and spud. In most polite circles, the union of fish and cheese has long been frowned upon. But, mi dispiace, Italian friends—it's time to reconsider this taboo pairing. The dish, as comforting as a hug and a roaring hearth on a rainy Dublin day, is all the convincing we need.
- 3 tbsp. unsalted butter
- 1 medium white onion, sliced 1/4″ thick
- 1 1⁄2 lb. finnan haddie (cold-smoked haddock), skin removed
- 3 cups heavy cream
- 2 lb. russet potatoes, peeled and cut into 1″ pieces
- Kosher salt and freshly ground black pepper, to taste
- 6 oz. aged cheddar, shredded
- 1⁄4 tsp. freshly grated nutmeg
- Roughly chopped parsley, for garnish (optional)
Melt butter in a 12″ skillet over medium. Cook onion until golden, about 18 minutes. Transfer onion to a bowl; set aside. Wipe skillet clean. Add haddock and cream; simmer 10 minutes. Transfer haddock to a plate; set aside. Simmer cream until reduced by two-thirds, about 15 minutes. Transfer half the cream to a bowl; set aside. Stir reserved onions into cream in skillet; set aside.
Bring potatoes to a boil in a 4-qt. saucepan of salted water; reduce heat to medium and cook until tender, about 15 minutes. Drain potatoes and return to pan. Add reserved cream, the cheddar, nutmeg, salt, and pepper; coarsely mash.
Heat oven to broil. Spread potato mixture in a 9″ x 13″ baking dish or individual ramekins. Add haddock and spoon onion mixture over the top; broil until browned, 2–3 minutes. Garnish with parsley, if you like.