Recipe from Around My French Table by Dorie Greenspan

Eight times out of ten, when I pick up celery root in a market in the United States, someone asks me what it is. I rarely see recipes for it, and I can’t remember when I was ever served celery root in a friend’s home. Not so in France, where the sweet, fresh, and just-a-little-green flavor of celery root is prized, mostly for its role in céleri rémoulade (shredded celery root mixed with a zesty mayonnaise dressing) but also in soups and stews — it can be added to any stew in which you’re using other root vegetables, like potatoes, turnips, or parsnips.

For this recipe, the celery root is cooked, then whirred in a food processor. The result is a smooth ivory puree with a soft, surprising flavor — you’ll think it’s celery, but you won’t be sure. Because the flavor is subtle, complex, and just a little sweet, the puree is the perfect accompaniment to fish, meat, or poultry, whether it’s a main dish that is robust and big flavored or one that is light and mild.

Makes 6 servings

Ingredients

• 3 cups whole milk
• 3 cups water
• Salt
• 2 celery roots, about 1 ¼ pounds each, peeled and cut into 2-inch cubes
• 1 medium Idaho (russet) potato (about 10 ounces), peeled and cut into 2-inch cubes
• 1 small onion, quartered
• 5 tablespoons unsalted butter, cut into 5 pieces, at room temperature
• Freshly ground white pepper
• Snipped fresh chives, pistachio oil (see Sources), or browned butter (see below), for serving (optional)

Directions

1. Bring the milk, water, and 1 tablespoon salt to a boil in a large pot — keep an eye on the pot, because milk has a tendency to bubble up furiously. Drop in the celery root, potato, and onion, adjust the heat so that the liquid simmers steadily, and cook for about 30 minutes, or until the vegetables are tender and can be pierced easily with the point of a knife. Drain, discard the liquid, and shake the colander well to remove as much liquid as possible.

2. In a food processor, in batches if necessary, puree the vegetables until perfectly smooth. Add the butter and whir until completely incorporated. Taste and add salt and white pepper as needed.

3. Transfer the puree to a warm serving bowl and, if you’d like, top with a generous shower of snipped chives or a drizzle of pistachio oil or butter that’s been cooked over low heat until its color is honey brown. Serve immediately.

Serving
Like mashed potatoes, this puree is fine served in a bowl that can be passed at the table, but, again like mashed potatoes, it’s also a good base, so think of it when you want to serve a one-dish main course — you can never go wrong with a combo like celery root puree topped with short ribs.

Storing
Leftover puree can be refrigerated for up to 3 days or packed airtight and frozen for up to 2 months. To reheat, warm the puree in the top of a double boiler or in a microwave oven.