Upon starting this recipe for potatoes au gratin with leeks I didn’t think about it being a crowd-friendly dish that could feed a ton of people. In all honestly, I had bought some gorgeous leeks from the supermarket, and I was trying to think of something to make. Usually, when we have leeks in the house, Emery is planning on making his Chicken and leek soup, which I love.
However, I had purchased some potatoes and was thinking about making scalloped potatoes with a rich bechamel sauce.
All of a sudden I realized that I had the perfect dish for the leeks all along. Potatoes Au Gratin with leeks.
Now, it seems obvious, but at the time I wasn’t putting two and two together. You see, potatoes and leeks have been paired together for a really long time as a soup. I wish I could take credit for this, but this vegetable soup has roots not only here in America, but also France, Romania, and Wales. If you’ve never heard of Vichyssoise, then I recommend that you seek it out and give it a try. It’s a potato and leek soup that can be served either cold or hot, and usually has a touch of cream in it.
So, when I was thinking what to make looking at a bag of potatoes and also leeks I couldn’t believe it wasn’t obvious, to begin with.
This version isn’t a soup at all, but a casserole or gratin with milk and a little bit of cheese added to the stars of the show; leeks and potatoes.
When starting I took a few minutes and pulled out the mandoline. I wanted to make sure my potato slices were even, and fairly thin. As I cut them I added them to a large bowl of cold water to preserve the potatoes without them oxidizing and turning brown. It actually is a helpful tip I learned years ago as a prep cook at a restaurant. You can also use this method when prepping large batches of potatoes to cook later without losing their crisp texture.
I’ve noticed that most gratins have a lot of cheese I decided against that for this. I wanted the leeks and potatoes to be the star without competing with the cheese, plus the bechamel sauce adds a ton of richness. Actually, it’s one of my favorite sauces to make. The versatility to use it is endless with recipes, as it can be used as a base for cheese sauce, alfredo sauce, or a creamy soup. No wonder it’s one of the mother sauces in French cooking.
After I layered my potatoes, I layered my leeks and bechamel sauce like a lasagna with a finishing layer of parmesan cheese before adding it to the oven. This dish baked up bubbly, browned on top, and creamy. It was definitely a hit!
Potatoes Gratin with Leeks
- 1 1/2 pounds of potatoes, washed and peeled
- 2 leeks (washed and chopped thinly)
- 1 stick unsalted butter
- 4Tablespoons of all-purpose flour
- 6 cups of milk
- 1/8 teaspoon of ground nutmeg
- 1 teaspoon of dried thyme
- 1 teaspoon of garlic powder
- 1 teaspoon of salt
- 1/2 cup of grated parmesan cheese
- chopped parsley (optional)
- Step 1 Preheat oven to 350 degrees F.
- Step 2 Wash leeks to remove any dirt or sand. Slice thinly crosswise into small pieces. Slice the potatoes on a mandolin or with a sharp knife into thin pieces, about 1/8 inch.
- Step 3 In a large skillet melt 1 tablespoon of butter and sauté the leeks and thyme. Season with salt, pepper, and garlic powder. Stir and cook over medium heat until leeks have started to brown. Remove the pan from the heat and let it cool.
- Step 4 In a large pot melt the remaining butter and add flour until incorporated. Slowly add the milk to the butter mixture while whisking. As it comes together the sauce will start to thicken. Once it coats the back of a spoon, then remove it from the heat, and stir in the nutmeg.
- Step 5 In a large greased casserole dish layer 1/3 of the potatoes on the bottom, add 1/2 of the leek mixture, pour over 1/3 of the sauce. Continue layering until the last layer is the sauce. Sprinkle with parmesan cheese and chopped parsley.
- Step 6 Cover casserole dish with aluminum foil, and bake for 45 minutes. Remove foil and bake until browned on top.
- Step 7 Let cool before serving. Enjoy!