Swiss Chard and Mustard Sardine Gratin

The balance of cream, cheese, greens and crunch makes this gratin a perfect side dish for holiday meals. Mustard and sardines add a boost of flavor, while the fresh breadcrumbs on top keep ’em coming back for more. If you can’t find enough Swiss chard at the end of the growing season, you can replace it with spinach, kale or any other hearty green. Frozen greens can be used as well. Sourdough bread is a good choice for the topping, but any bread will work.

By Ashley Swartzendruber / Photography By Ashley Swartzendruber | November 09, 2020

Ingredients

5 tablespoons unsalted butter, divided
1½ pounds Swiss chard
1 garlic clove, thinly sliced
2 tablespoons all-purpose flour
½ cup whole milk
½ cup heavy cream
2 tablespoons whole grain mustard
1 tablespoon Dijon mustard
1 tablespoon lemon juice
⅛ teaspoon ground nutmeg
Pinch of ground black pepper
2 4-ounce cans mustard-flavored sardines
1 cup shredded Gruyère cheese
2 cups finely diced day-old sourdough bread
½ cup grated Parmesan cheese
Fresh herbs for serving such as dill or parsley, optional

Instructions

Serves 4–6

Preheat the oven to 400°. Grease the inside of a 10-inch baking dish with 1 tablespoon of butter and set aside.

Bring a large pot of salted water to a boil. While the water heats, remove the Swiss chard stems and reserve about 2 cups of them, discarding any that are thin, limp or brown. Cut the reserved stems in half lengthwise and chop into 1-inch pieces. Roughly chop the leaves, keeping them separate from the stems. Boil the stems for about 5 minutes. Add the chopped leaves and boil 1 minute more. Drain and let cool, squeezing out as much moisture as possible.

Melt 2 tablespoons of butter in a medium saucepan over medium-low heat. Add the garlic, stirring constantly, and sauté for about 30 seconds or until lightly browned but not burnt. Add the flour and stir for about 30 seconds. Whisk in milk, cream and mustard; cook until thickened, stirring constantly, 2 to 3 minutes. Whisk in the lemon juice, nutmeg and black pepper. Remove from heat and stir in the Swiss chard greens and stems.

Spread the Swiss chard mixture into the buttered dish. With a fork, roughly break apart the sardines and nestle them into the Swiss chard mixture. Sprinkle Gruyère cheese evenly on top.

Melt the remaining 2 tablespoons of butter. In a bowl, mix the breadcrumbs, melted butter and Parmesan cheese. Sprinkle over the gratin. Bake for 30 to 35 minutes or until the top is golden brown and the cheese is bubbling. Top with fresh herbs and serve.

Edible Michiana original recipe