Michel Guérard discovered that a small amount of rice amps up creaminess in a puree while ensuring that none of the flavor of the vegetable -- in this case, celeriac -- is lost. Alexandra Stafford of the blog Alexandra Cooks, who tipped us off to the technique, says it also works well with any surly, fibrous root, and is especially delicious with turnips. Recipe adapted very slightly from La Cuisine Gourmande (William Morrow & Company, 1979). —Genius Recipes
Peel celeriac and cut into cubes. Place celeriac pieces into a saucepan and add milk, salt, and pepper.
Bring the liquid to a boil over high heat, and add the rice. Stir for one minute. Lower the heat, partially cover the pan, and simmer for 20 minutes.
Once the rice and celeriac are cooked, pour them into a colander. Save their cooking liquid in a bowl.
Place rice and celeriac in a blender or food processor, add 1 tablespoon of cream, and blend for 3 minutes. Add remaining cream as vegetables are being blended.
To thin the purée, add a bit of the reserved cooking liquid (approximately 3/8 cup), and blend for another minute. Taste for salt and pepper. (Note: You can save and freeze any remaining cooking liquid to add to soup.)
If not served immediately, keep warm in a bain marie or double boiler, or reheat over very low heat before serving.