- 2 tablespoons butter, plus extra for dish
- 1 cup sliced shallots
- 3 cloves garlic, minced
- 2 teaspoons chopped fresh thyme
- 1 cup whole milk
- 1/2 cup heavy cream
- Salt and pepper, to taste
- 1 pound Yukon Gold potatoes, cut into 1/8-inch slices
- 1/2 pound rhubarb, cut into 1/8-inch slices
- 1/2 cup grated Fontina cheese
- 1/4 cup crumbled blue cheese
Preheat oven to 375° F. Lightly butter a 9-inch square baking dish.
Melt butter over medium heat in a saucepan. Add shallots and cook until soft, about 7 minutes. Stir in garlic and thyme; cook until fragrant, about 2 minutes. Pour in milk and cream and bring to just a simmer. Remove from the heat and season with salt and pepper.
Layer potatoes and rhubarb slices in the prepared baking dish, seasoning each layer with salt and pepper. Pour warm milk mixture over the top and sprinkle with cheeses.
Bake until vegetables are tender and the top is golden brown, about 45 minutes.