Sardine and Swiss Chard Gratin

Ingredients

• Kosher salt and freshly ground black pepper, to taste
• 1½ lb. Swiss chard, stemmed, leaves torn into 2″ pieces
• 4 tbsp. unsalted butter, plus 2 tbsp. melted
• 2 tbsp. olive oil, plus more
• 8 cloves garlic, thinly sliced
• 2 shallots, thinly sliced
• ½ cup flour
• 2½ cups milk
• 1 cup heavy cream
• 1 cup shredded Gruyère
• ¼ tsp. freshly grated nutmeg
• 3 eggs, beaten
• 2 (4-oz.) cans sardine fillets packed in oil, drained
• ½ cup panko bread crumbs

Instructions

1. Cook chard in salted boiling water until wilted, 1–2 minutes. Drain, let cool, and squeeze dry. Heat 4 tbsp. butter plus oil in a 4-qt. saucepan over medium-high heat. Cook garlic and shallots until golden, 5–7 minutes. Add flour; cook 2 minutes. Whisk in milk, cream, salt, and pepper; boil until thick, 2–3 minutes. Stir in chard, half the Gruyère, the nutmeg, and eggs.

2. Heat oven to 400°; grease an 8″ x 11″ baking dish with oil. Spread half the chard mixture into dish; top with half the sardines. Repeat layering. Stir melted butter and bread crumbs in a bowl; sprinkle over top with remaining Gruyère. Bake until golden and bubbly, about 30 minutes.