Hashbrown Casserole

Soup:
2 tablespoons unsalted butter
1/2 yellow onion, chopped
1 stalk celery, chopped
1 carrot, chopped
1/4 cup white whole wheat flour
3 cups chicken stock
1 Tbsp. Italian seasoning
1 bay leaf
1/4 cup milk
1 teaspoon sea salt

2 pounds russet potatoes, grated
4 Tbsp. melted unsalted butter
1 teaspoon sea salt
1/4 teaspoon pepper
1 cup sour cream
1 cups cheddar cheese

Preheat oven to 350 degrees and adjust rack to middle position. Melt the butter in a large pot over medium heat. Add the onion, celery, and carrots and cook for 12 minutes, stirring occasionally until softened. Add flour and cook stirring with a wooden spoon for 2 minutes. Pour in the chicken stock, stir, and bring to a boil. Add seasonings, lower the heat and simmer for 15 minutes.

Remove broth from heat and stir in milk and sea salt. Pour soup into a blender and blend until smooth (or use immersion blender). Pour soup back into the large pot. Add potatoes, butter, sea salt, pepper, sour cream and 1/2 of the cheese to soup and stir until combined. Pour mixture into a large baking dish and top with remaining cheese. Bake for 40 minutes until bubbling and golden brown. Cool for 15 minutes before serving.