Ingredients
6 Yukon gold or russet potatoes (2 pounds/1 kg)
1 small or medium onion slices thin
For the sauce:
1/4 cup butter
1/2 tsp minced garlic (optional)
1/4 cup all-purpose flour
1 tsp salt
1/2 tsp pepper
1/2 tsp dried thyme or marjoram
2 & 1/2 cups milk
Preparation
Sauce: Melt butter in saucepan over medium heat. Add Garlic, flour, salt, pepper and thyme. Cook, stirring for 1 minute. Gradually whisk in milk. Cook, whisking constantly, 5 to 8 minutes or until boiling and thickened. Set aside.
Peel and thinly slice potatoes about 1/8 inch thick. Arrange 1/3 in a greased 8" square glass baking dish or casserole. Spread 1/2 the onion over top. Repeat layers. Arrange remaining potatoes over top. Pour sauce over top.
Cover and bake in preheated oven at 350 F for 1 hour. Uncover and bake 30 minutes longer or until lightly browned and potatoes are tender. Let stand 5 minutes before serving.
