Vegan Potato Gratin
This Vegan Potato Gratin is creamy, comforting, and completely dairy-free. Made with thinly sliced potatoes and a rich cashew-based garlic sauce, this plant-based potato gratin bakes up tender with a golden, slightly crisp top—perfect for holidays or cozy weeknight dinners.
Ingredients
- For the Potatoes:
- 2½ pounds Yukon Gold or Russet potatoes thinly sliced (about ⅛-inch thick)
- 1 small yellow onion thinly sliced
- 3 cloves garlic minced
- 1 tablespoon olive oil for greasing dish
- For the Creamy Vegan Sauce:
- 1 cup raw cashews soaked in hot water 30 minutes, drained
- 1½ cups unsweetened plant-based milk almond, oat, or soy
- 2 tablespoons nutritional yeast
- 1 tablespoon lemon juice
- 1 teaspoon salt
- ½ teaspoon black pepper
- ½ teaspoon dried thyme
- Pinch of nutmeg
Instructions
- Preheat Oven
- Preheat oven to 375°F (190°C).
- Lightly grease a 9x13-inch baking dish with olive oil.
- Prepare Potatoes
- Slice potatoes evenly to about ⅛-inch thick.
- Thinly slice onion and mince garlic.
- Do not rinse potatoes after slicing—the starch helps thicken the sauce.
- Make the Creamy Sauce
- Add soaked cashews, plant-based milk, nutritional yeast, lemon juice, salt, pepper, thyme, and nutmeg to a high-speed blender.
- Blend until completely smooth and creamy.
- Taste and adjust seasoning if needed.
- Sauce should be silky and pourable.
- Assemble the Gratin
- Layer half of the potatoes in the baking dish.
- Sprinkle with half the onion and garlic.
- Pour half the sauce evenly over the top.
- Repeat with remaining potatoes, onion, garlic, and sauce.
- Gently press down so sauce settles between layers.
- Bake
- Cover tightly with foil.
- Bake for 45 minutes.
- Remove foil and bake an additional 20–25 minutes until top is golden and potatoes are fork-tender.
- Optional: Broil 2–3 minutes for extra browning.
- Rest
- Let rest 10–15 minutes before serving to allow sauce to thicken.
Notes
- Slice potatoes evenly for uniform cooking (a mandoline helps).
- Soaking cashews ensures a smooth, creamy sauce.
- Do not skip resting time—this helps the gratin set.
- If reheating, add a splash of plant-based milk to prevent drying.
- Can be assembled up to 24 hours in advance and baked when ready.
- Freezing is possible up to 1 month, though texture may soften slightly.