In this French casserole, oil-packed canned sardines are layered with creamy Swiss chard and baked under a crunchy layer of bread crumbs.
- 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
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.