Leek, Potato, and Celery Root Gratin

A gratin is such a good way to sneak in vegetables: they may be surrounded by lots of cream and cheese but you’re still getting a few of your five a day! This is always a crowd-pleaser; it has a rich, velvety texture from the potato and the celery root and a lovely sweetness from the leeks. Children always seem to enjoy this one so it’s a perfect way to get them eating the vegetables they might not usually eat. It’s also quite fun to assemble and a great way to get them involved in the kitchen.

SERVES 4 TO 6

Gluten-Free

INGREDIENTS

Cooking Fast and Slow: Easy, Comforting, (Mostly) Plant-Based Recipes for Busy People Natalia Rudin

• 1 tbsp olive oil

• 1 tbsp butter (or vegan alternative)

• 2 leeks (14 oz / 400 g), halved lengthwise and sliced into half-moons

• 1 1⁄2 cups (360 ml) heavy cream of choice

• 1 ¼ cups (300 ml) unsweetened milk of choice

• 2 sprigs of rosemary, needles finely chopped

• 1 large bay leaf

• 1⁄2 tsp grated nutmeg

• 1⁄4 vegetable stock cube, crumbled

• 1 whole celery root (1 lb 9 oz / 700g)

• Juice of 1⁄2 lemon

• 2 large potatoes (1 lb 5 oz / 600g)

• 1 ¾ cups (200g) grated cheddar, or cheese of choice

• Salt and black pepper

• Chopped green onions, to serve

DIRECTIONS

1. Preheat the oven to 375°F.

2. Heat the olive oil and butter in a frying pan and fry the leeks over low heat until soft. Set aside 3 tablespoons of the cream and add the rest to the leeks along with the milk, herbs, nutmeg, and stock cube. Let this simmer very gently for 10 minutes, then remove from the heat and allow to infuse for 10 minutes.

3. Meanwhile, peel the celery root and cut in half, then cut into thin (⅛-inch / 3 mm) slices. Drop the slices into a bowl of water with lemon juice in it to prevent them from discoloring. In a separate bowl, do the same with the potatoes.

4. Spoon a layer of the creamy leek mixture into the bottom of a large ovenproof dish and add a layer of the celery root on top followed by some grated cheese. Spoon over another layer of the leeks and cover with a layer of potato. Repeat this process, alternating between the celery root and potato, until everything is used up, ending with celery root or potato as the top layer.

5. Pour the reserved cream over the top, season with salt and pepper, and add a final sprinkling of cheese. Bake in the oven for 1 hour, until browned and bubbling. Let stand for 10 minutes, top with green onions, and serve.

TIP: I would enjoy this as a main, but it works perfectly alongside a roasted meat dish.

Reprinted with permission from Cooking Fast and Slow by Natalia Rudin, copyright © 2025. Published by Ten Speed Press, a division of Penguin Random House, LLC.

When you shop using our links, we earn a small commission. It’s a great way to support public media at no extra cost to you.