Combine the celery root, potaotes, turnips, and leeks
in a large saucepan and cover with cold water. Place
over medium-high heat and bring to a boil. Reduce heat
and simmer until all of the vegetables are tender,
about 30 mins. Drain well and pass the vegetables
through a ricer. Add salt and pepper to taste. Divide
among 4 plates and serve immediately.
