Ingredients

Makes 20 servings

　　2 heads garlic, top 1/3 trimmed to expose cloves

　　2 tablespoons olive oil

　　1 1/4 teaspoons kosher salt

　　1/4 teaspoon plus 1/8 teaspoon freshly ground black pepper

　　2 tablespoons canola oil

　　10 heads celeriac, roughly chopped (about 7 1/2 pounds total)

　　8 tablespoons butter cut into 8 pieces plus more if needed

　　2 cups celery, peeled and finely minced (about 6 stalks)

　　

Step 1

Preheat oven to 375°F.

　　

Step 2

Place garlic in small baking dish. Drizzle with olive oil and sprinkle with 1 teaspoon salt and 1/8 teaspoon pepper. Cover tightly with foil and roast until golden brown and fragrant, about 50 to 60 minutes. Uncover dish and cool garlic, then squeeze softened cloves into small bowl and set aside.

　　

Step 3

In heavy stockpot over moderate heat, heat canola oil. Add celeriac and sauté, stirring frequently, until starting to soften, about 8 minutes. Add water just to cover, raise heat to high, cover, and bring to boil. Reduce heat to moderate and simmer until celeriac is easily pierced with fork, about 20-30 minutes. Drain celeriac, reserving liquid, and transfer to food processor. Add roasted garlic. Turn motor on, then slowly add butter, 1 piece at a time, pureéing until smooth. Pureé should appear slightly thinner than mashed potatoes. If too thick, add small amount reserved cooking liquid, 2 tablespoons at a time. If too thin, add additional butter, 1 tablespoon at a time.

　　

Step 4

Sprinkle remaining 1/4 teaspoon salt and remaining 1/4 teaspoon pepper over pureé, then fold in celery. Serve immediately.