I originally took these pics for an upcoming post on my go-to cheese but this vegan potato au gratin definitely deserves a post! It’s everything you’d expect from a dairy-laden potato au gratin and is, really, as creamy as physically possible due to the vegan half and half made from one part silken tofu and one part soy milk. It’s a trick I utilize all the time (like in my Vegan Tomato Basil Bisque) but rarely see in other’s recipes. I also use a dash of homemade umami powder made from dehydrated shiitake mushrooms which contain 1,060 mg of glutamate per 100g (right around that of a high quality, aged parmesan cheese) to make this vegan potato au gratin the utmost savory and satisfying. January in Wisconsin calls for dishes like this!
This vegan potato au gratin is really special, suitable for a dinner party or holiday meal and can be made up to 3 days ahead of time (for that, I recommend reserving ~1 cup of the cream sauce to pour on when reheating. Bake as instructed, minus the broiling step. Let cool under the foil, then add the cream sauce and the foil again, then place in the fridge).
Vegan Potato au Gratin
serves 5 well
6 russet potatoes, sliced super thin (ideally using a mandolin) and soaked in very hot water
2 cups vegan half and half (to make: blend 1 cup silken tofu and 1 cup soy milk)
3 tbsp vegan butter (or use olive oil for lower saturated fat but works equally well)
3 tbsp all purpose flour (or sub gluten free flour)
1/4 tsp black pepper
1/2 a red onion or 2 shallots, diced
1 tbsp fresh thyme (some reserved for garnishing)
5 garlic cloves, diced
1 tsp salt
1 cup vegan mozzarella (my go-to recipe can be found on my Mac and Cheese post here)
Optional but strongly recommend: 2 tbsp umami powder (made from blending 1 cup dehydrated shiitakes, 1/4 tsp garlic powder and 1/2 cup nutritional yeast)
Preheat oven to 350.
Make a roux from the butter and flour. Stir in the onions, garlic, salt and pepper and let cook for a minute before adding the 2 cups of half and half. Stir in the umami powder, thyme (reserving some for garnishing) and 1 cup of vegan mozzarella. Add to a blender and blend until smooth. Drain the potatoes from the hot water, then in a large bowl pour the blended cream sauce over them, stirring to coat each slice well. Layer the potato rounds in your baking dish, then pour the remaining cream sauce over, making sure the potatoes are nearly completely submerged. Wrap in foil and bake for 60-75 minutes. Remove foil and broil for 10 more minutes. Garnish with the remaining thyme.