Leek and Spring Onion Gratin
Lighter than a potato gratin, but still luscious from heavy cream and cheese, this allium-rich dish has a crunchy bread crumb and anchovy topping to take it over the top. If you can’t find spring onions — newly harvested onions often sold with the green stems still attached — use regular onions or shallots. Or try red onions for a shot of bright color among the soft greens and golds in the pan. Serve this as a side dish with grilled or roasted meats or fish.
- Total:
- Serves: 6 persons
Ingredients
- 3scallions, thinly sliced
- 2stalks green garlic or 2 garlic cloves, thinly sliced
- ½teaspoon fine sea salt, more as needed
- ¼teaspoon black pepper
- 3leeks, white and light green parts only, halved lengthwise and cut into 1-inch pieces crosswise
- 2spring onions, cut into 1-inch wedges
- 3tablespoons butter, cut into cubes
- 5anchovies, minced
- ⅓cup grated Parmesan cheese
- ⅔cup panko bread crumbs
- 1teaspoon thyme leaves, finely chopped
- 1teaspoon finely grated lemon zest
- Pinch of red pepper flakes
- 1tablespoon extra-virgin olive oil, plus more for drizzling
- 4ounces Gruyère, coarsely grated
- 1cup heavy cream
Instructions
Step 1
Place a rack in the top third of oven and heat to 400 degrees. In a medium bowl, toss scallions, green garlic, salt and pepper.Step 2
Heat a 12-inch cast-iron skillet over medium heat. Arrange the leeks cut-side down in the skillet, then scatter spring onions in the gaps. Sprinkle a little more salt on top, then spread scallion mixture in an even layer in pan. Pour in 1/4 cup water and top with butter.Step 3
Cover and and simmer on low heat until vegetables are soft, 20 to 25 minutes.Step 4
Uncover the pan, turn heat to medium-high and cook until liquid is evaporated and edges are starting to brown and sizzle, 5 to 10 minutes longer.Step 5
Meanwhile, in a small bowl, rub together anchovies, Parmesan, panko, thyme, lemon zest and red pepper flakes. Drizzle in oil and toss to combine.Step 6
Sprinkle Gruyère evenly into skillet over leeks, pour in cream, then top with the bread crumb mixture. Drizzle with a little more oil. Transfer to oven and bake until golden and bubbly, 15 to 20 minutes. Cool slightly, then serve warm.