Root vegetable puree

Ingredients:

• 340 g of Russet Burbank potatoes (1 or 2 medium tubers)
• 340 g parsnips (about 2 medium roots)
• 340 g celery root (about 1 medium root)
• 230 g turnips (about 2 medium roots)
• 10 tbsp butter, cut into small pieces

Preparation:

1. Peel the potatoes, parsnips, celery, and turnips. Cut into 2.5-5 cm (1-2 in) pieces. Combine the vegetables in a large saucepan and cover with cold water to a depth of twice that of the potatoes. Add 1 tablespoon of salt. Bring the water to a boil over high heat, reduce to medium, and simmer until the vegetables are tender, 20-30 minutes (insert a paring knife into the potatoes and make sure the blade goes in easily).
2. Drain the vegetables completely and return them to the pan. Simmer for 5 minutes to evaporate any excess liquid. Pass the hot vegetables through a vegetable grinder over a large bowl. Add 1.5 teaspoons of salt, then whisk in the butter.