If using dried herb, add it with the water or broth. You don’t have to purée the soup, if you don’t want to. Just omit that step and continue with the recipe. You’ll want to finely chop or dice the vegetables in that case.
2 T vegetable oil
2 T butter
3 medium carrots, chopped
1 large onion, chopped, or 2 c chopped leeks, white and pale green parts only
1 large potato or 2 medium, chopped
1 large turnip, or 2 medium, chopped
4 c water or broth
salt and pepper, to taste
1-inch piece fresh ginger, peeled and grated
1-1/4 c milk
3 T cream, or 3 T additional milk
2 T fresh herb, chopped or 2 t dried herb (see headnote)
1 – 2 T lemon juice or sherry vinegar
1. Put oil and butter in a large saucepan or soup pot over medium heat. Once the butter has melted, add carrots, onion, potato, parsnip, and turnip. Sauté for 5 minutes, then turn heat to low, cover, and sweat vegetables for about 15 minutes, stirring occasionally.
2. Pour in the water or broth, dried herb, if using, and add some salt and pepper. Increase heat, and bring to the boil. Cover, reduce heat, and simmer for 20 minutes, or until the vegetables are soft. Strain vegetables, reserving cooking liquid. Add ginger to vegetables, then transfer to a food processor or blender and purée.
3. Return the purée and cooking liquid to the pan. Stir in the milk and gently reheat. Don’t bring to a boil, just to a barest simmer. Remove from heat and stir in cream, fresh herb, and lemon juice or vinegar. Taste for seasoning.