A delicious, creamy side dish featuring leeks, carrots and potatoes layered between cheese and a creamy sauce. A perfect side for any feast. Assemble a day ahead and cook the day of the feast.
Prep Time15 minutesmins
Cook Time50 minutesmins
Total Time1 hourhr5 minutesmins
Course: Side Dish
Cuisine: French
Keyword: leeks, potato au gratin, Thanksgiving side dish
Servings: 8people
Calories: 562kcal
Author: Getty Stewart
Ingredients
3Tbspbutter, divided
3mediumleeks, thinly sliced
2clovesgarlic, minced
2Tbspall purpose flour
11/2cupswhole milk
1/2tsp salt
1/4tsp black pepper
1/4tspdry mustard powder
2sprigsfresh thyme (1/2 tsp dried)
3largered or white potatoes (1 lb), thinly sliced (1/8 inch)
Preheat oven to 375°F/ 190°C and generously grease or butter a 21/2 quart/litre baking dish.
In medium pan, sauté leeks in 1 Tbsp butter until tender, about 5-7 minutes.
Add garlic and sauté another 1-2 minutes.
Remove leeks from pan and set aside.
In same pan, melt remaining 2 Tbsp butter.
Mix in flour until all of the butter is absorbed.
Gradually whisk in milk to make a smooth sauce.
Add salt, pepper, mustard powder and thyme. Stir and heat until sauce is thick and smooth. Taste and adjust seasoning to your liking. Remove from heat.
Assembly & Baking
Layer the gratin in prepared dish in thirds. Start with 1/3 potatoes, leeks, carrots, top with 1/3 cheese, top with 1/3 sauce. Repeat two more times finishing with sauce.
Bake, covered for 30 minutes. Uncover and bake another 25 to 30 minutes until vegetables are tender. To test tenderness, insert a knife through layers.
Remove from oven and let rest for 10 minutes to set. Garnish with fresh chives or parsley.
Notes
Want to change the cheese - go for it! Use your favourites.Want to skip the carrots - no problem. Make this gratin the way you want!Want to add a layer of bread crumbs and parmesan on top - that would be mighty tasty and a classic au gratin touch.