2 leeks, tops removed, cleaned, halved lengthwise
2 cups vegetable stock
4 Tablespoons unsalted butter
1 cup walnuts
½ cup parsley, picked
Zest of 2 lemons
Preheat the oven to 400 degrees.
In a No.8 or No.10 Skillet, heat 2 tablespoons of olive oil until shimmering, over medium heat. Add the leeks, cut side down and cook until golden brown, 4 to 5 minutes. Season with salt and pepper.
Add the vegetable stock and cook until it reachers a simmer. Cover with a (parchment) lid. Reduce heat, so that the liquid is barely simmering, and cook until leeks are tender, 20-25 minutes.
Meanwhile, put the walnuts onto a baking sheet and toast in the oven until golden and fragrant, 5-10 minutes, checking frequently. Remove from oven and set aside until cool. Roughly chop the walnuts.
Remove the lid from the leeks and gently swirl the butter into the stock until it is emulsified.
Transfer from skillet to serving dish. Top the leeks with a drizzle of olive oil, salt, and pepper. Finish with a squeeze of lemon juice, the lemon zest, walnuts, and sprigs of parsley. Serve immediately.