New! Hazelnut Hasselback Potato Gratin view recipe

Hazelnut Hasselback Potato Gratin

Potatoes are essential to our holiday and celebration table, and for the past few years, this has been our chosen dish. This rich vegan gratin is perfumed with leeks and rosemary, and smothered in a velvety hazelnut cream. While you can use store-bought hazelnut milk, I always make my own (see Notes below for instructions)—I like the pronounced nuttiness of homemade hazelnut milk, which delivers a creamy béchamel-like sauce that is still light.

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A square baking dish containing scalloped potatoes in a creamy sauce, garnished with fried sage leaves. - Hetty Lui McKinnon

Use the whole leek, including the green leaves that many recipes ask you to discard—these are slightly tougher than the tender whites, but this dish cooks in the oven for over an hour, plenty of time for them to soften.

This recipe originally appeared in Tenderheart: A Cookbook About Vegetables and Unbreakable Family Bonds. © 2023 by Hetty Lui McKinnon. Excerpted by permission of Alfred A. Knopf, a division of Penguin Random House LLC. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher

Hazelnut hasselback potato gratin

Serves

Ingredients

42 grams regular or vegan butter
30 grams rice flour or all purpose flour
750 milliliters hazelnut milk (see Note below)
1 garlic clove, finely chopped
pinch of freshly grated nutmeg
1 sprig of rosemary, leaves picked and finely chopped
1 tablespoon soy sauce or tamari
sea salt and black pepper
1 leek, white and green parts finely sliced and washed well
extra-virgin olive oil
1.5 kg russet or Yukon gold potatoes scrubbed
15-20 sage leaves

Instructions

Preheat the oven to 350°F (180°C). You’ll need an ovenproof dish— I use an 8 ½-inch (22 cm) square baking dish, but you can size slightly up or down.
Heat a saucepan over medium heat and melt the butter. Gradually add the flour, a tablespoon at a time, whisking constantly to prevent burning or clumps. When well combined with the melted butter, add the hazelnut milk and 1 cup (240 ml) of water and whisk constantly for 2–3 minutes, until creamy and slightly thicker (you want the consistency of heavy cream). Whisk in the garlic, nutmeg, rosemary, soy sauce or tamari and season well with sea salt and black pepper. Remove from the heat and set aside.
Place the leek in the ovenproof dish, drizzle with some olive oil, season with sea salt and black pepper and toss. Press the leek into an even layer, then add ½ cup (120 ml) of the hazelnut cream and smooth it out with the back of a spoon.
Next, finely slice the potatoes using a mandoline or sharp knife (a mandoline makes this job so much easier and quicker). As you are slicing, try to keep the potatoes in a neat stack. Arrange the stacks of potato in the dish, edge-side up, until the dish is full. I usually like to place the stacks in an alternating crisscross pattern, but you can simply line them up across the dish or in a circular pattern—it’s up to you. The potato should be tightly packed.
Pour the remaining hazelnut cream over the potatoes, drizzle with olive oil and season with sea salt and black pepper. Place the dish on a sheet pan to catch any drips, then cover with foil and bake for 1 hour.
Meanwhile, place the sage leaves in a small bowl, drizzle with olive oil and season with a pinch of salt.
After 1 hour, remove the foil from the potato and scatter on the sage. Increase the oven temperature to 420°F (230°C) and bake for another 15–20 minutes, until the potatoes are golden and bubbling, and the sage leaves are crispy.
Serve with a green salad or steamed veggies.

Tips and Variations

To make your own hazelnut milk, soak 1 cup of hazelnuts in boiling water for 30 minutes. Drain, then place the hazelnuts in a high-powered blender or food processor. Add 1 grated garlic clove and 2 cups (480 ml) of water (or vegetable stock, if you want more flavor) and blend until completely smooth. A high-powered blender will give you the smoothest results. This will yield 3 cups plus 2 tablespoons (750 ml) of hazelnut milk, enough for this recipe.

Substitute • hazelnut milk: cashew milk • leek: yellow onion • sage: rosemary

Vegetable swap • potato: sweet potato, taro