Potato Gratin with Mustard and Gruyere Cheese

3 1/2 pounds russet potatoes, peeled, cut into 1/8-inch-thick slices
1 1/2 tsp. dried dill weed
3 cups grated Gruyere cheese (about 10 ounces)
1 1/3 cups whipping cream
1 1/3 cups chicken stock or canned low-salt broth
1/4 cup Texas Traditions Jalapeño Pepper Mustard

Preheat oven to 400. Butter a 13x9x2 glass baking dish. Overlap 1/3 of potatoes in prepared dish. Season generously with salt and pepper. Sprinkle with 1/2 tsp. dill weed and 1 cup cheese. Repeat layering twice, using 1/3 of potatoes, 1/2 tsp. dill weed and 1 cup cheese for each layer.

Whisk cream, stock and mustard in bowl. Pour over potatoes. Bake until potatoes are tender and top is crusty and brown, about 1 hour.

Cool 10 minutes and serve.