Wild-looking celeriac (celery root) is a variety of celery cultivated for its large root instead of its stalks. Use it in place of celery in almost any recipe, or use this recipe and mash it into something decadent!

3 cups 1/2-inch dice peeled celeriac (celery root; from about one 18-ounce celeriac)
1 large potato, peeled, cut into 1 1/2-inch chunks (about 2 1/2 cups)
1/4 cup heavy cream
2 tablespoons (1/4 stick) butter

Cook celeriac in large saucepan of boiling salted water 15 minutes. Add potato and boil until celeriac and potato are very tender, about 15 minutes longer. Drain. Return to same saucepan; stir over medium-high heat until any excess liquid in pan evaporates, about 2 minutes. Add cream and butter; mash until mixture is almost smooth (or put through a ricer for great texture). Season to taste with salt and pepper.