Heat cast iron or enamel cast iron pan over medium to high heat. Add the extra virgin olive oil. When it is shimmering, add the leeks and cook 2 minutes. Then flip them over and cook for an additional 2 minutes on the second side.
Add in the ⅓ cup white wine and the chicken stock. then sprinkle the sea salt and fresh cracked black pepper over the leeks. Cover and simmer on low for 30 minutes.
While the leeks are simmering, mix together the finely chopped walnuts, parsley, parmesan, breadcrumbs and lemon juice in a bowl. Set this aside until you need it.
When the leeks are done remove them from the pan. Then turn the heat up to low- medium and reduce the broth in the pan by about ⅓.
Then add in ¼ cup white wine, the heavy cream, Dijon mustard, butter and capers. Continue to heat on low, stirring constantly until the butter is fully melted.
Then reduce the heat to simmer for 5 minutes. Continue to stir occasionally and make sure your butter does not begin to separate. The sauce will be thin but nice and creamy.
Once the sauce is done, spoon it over the leeks and then top the leeks with the walnut breadcrumb topping.
Serve with noodles, crusty bread or another main dish and season with sea salt and fresh cracked pepper to taste.
