Cook 1-2 chopped leeks in one tablespoon butter on medium heat, along with 3-4 chopped garlic cloves. Add 3-6 sliced turnips and cook on low heat, covered for 10-15 minutes (Japanese variety – 15-20 minutes for traditional purple-top variety).
Uncover and add 2l of milk (add some cream for a gourmet treat), and blend with a hand blender until smooth. Bring to the boil, add salt and pepper to taste and serve!
(Note: Multiple variations are possible – substitute 1 can coconut milk for 500ml of milk, and/or 1tbs curry powder, or 1 tsp miso).