Celeriac and Potato Puree
1 whole celeriac, approximately 112 pounds
1 pound russet potatoes, peeled
Blanc (recipe follows)
14 to 13 cup softened butter
13 to 12 cup cream or milk
Salt and pepper
With a sharp knife, trim and peel the celeriac and cut into 12-inch cubes. Place the cubes in acidulated water (water and lemon juice, for example) as you go to prevent darkening. Cube the potatoes and place them in acidulated water, as well, until you're ready to cook.
Bring the blanc to a boil. Drain the celeriac and potatoes and add them to the blanc. Cook uncovered, until very tender, approximately 15 to 20 minutes. Drain well, then mash into a puree, adding butter and cream, to taste. Adjust seasonings with salt and pepper. Make 6 servings.
BLANC: To prevent celeriac from darkening during cooking, it needs to be cooked in a blanc instead of water. Combine 1/4 cup flour, 1 quart water, 2 tablespoons lemon juice and 1 teaspoon salt.