Butter, for greasing the baking dish
2 tablespoons extra-virgin olive oil
1 large onion, chopped
2 large cloves garlic, chopped
1/3 cup almond milk
1/4 cup vegetable broth
1 teaspoon minced fresh rosemary
1 teaspoon Pink Himalayan Sea Salt
3/4 teaspoon freshly ground black pepper
1 pound Fingerling potatoes, cut 1/8-inch-thick using mandoline
1 cup grated parmesan cheese
1/2 cup grated manchego cheese
1/2 cup grated Stilton cheese with apricots (I got this from Trader Joe’s, but if you can’t find it you can always use the regular Stilton cheese or another type of cheese)
2 tablespoons chopped fresh parsley, optional
Preheat to 400 degrees F. Butter a 2-quart glass or ceramic baking dish.
Heat the oil in a large skillet over medium-high heat. Add the onions and cook until tender and golden, about 10 minutes. Add the garlic and stir 1 minute. Add the milk, broth, rosemary, salt and pepper. Remove the pan from the heat.
Mix all the grated cheeses together in a medium bowl.
Arrange one-third of the potato mixture in the bottom of the prepared baking dish. Sprinkle with one-third of the cheese mixture. Repeat the layers twice more ending with a layer of the cheese mixture. Pour the cream mixture over the layers and cover the pan with foil.
Bake the gratin until the potatoes are almost tender, about 45 minutes. Remove the foil and continue to bake until the potatoes are tender and golden on top, 20 to 25 minutes longer.
Remove from the oven and let the gratin rest, 10 minutes. Sprinkle with the chopped parsley and serve.