Servings: 8
Prep Time: 35 Min.
Cook Time: 1 Hour 20 Min.

+ 3 Tbsp. plus 1 tsp. unsalted butter, divided
+ 3 lb. Yukon gold potatoes, peeled and thinly sliced (1/8-inch thick)
+ 2 large shallots, thinly sliced (2 cups)
+ 1 Tbsp. minced garlic
+ 2 tsp. finely chopped fresh thyme
+ 3 Tbsp. all-purpose flour
+ 2 tsp. kosher salt
+ 1/2 tsp. freshly ground black pepper
+ 1 1/2 cups Kitchen Basics® Original Chicken Stock
+ 1 cup whole milk
+ 10 oz. Gruyere or aged white Cheddar cheese, grated, divided (2 1/2 cups)
+ 3 Tbsp. finely chopped chives or green onion

1. Set an oven rack to the middle position and preheat the oven to 400°F. Grease a 9x13-inch baking dish (shallow 3-qt.) with 1 tsp. butter. Scatter half of the shallots on the bottom of the pan, and shingle 1/3 of the potatoes on top; set aside.
2. Melt the remaining 3 Tbsp. butter in a large saucepan over medium heat. Add the garlic and thyme and cook about 1 minute until fragrant. Add the flour, salt and pepper; cook about 1 minute, whisking constantly, until combined and fragrant.
3. Gradually whisk in the stock until smooth, then whisk in the milk; bring to a simmer over medium-high heat. Reduce heat to low. Stir in 2 cups of the cheese until melted and smooth.
4. Pour 1/3 of cheese sauce over the potato layer. Scatter remaining shallots on top. Repeat layers of potatoes and sauce twice, then sprinkle with remaining 1/2 cup cheese.
5. Cover the pan with foil and bake 50 minutes. Uncover; continue to bake about 20 minutes longer until sauce is bubbling, cheese on top is golden brown and potatoes are tender when pierced with a paring knife. Let stand 10 to 15 minutes; sprinkle with chives before serving.

TIP: A mandoline makes quick work of slicing the potatoes evenly.