Heat oil in a large pot over medium heat. Add leek and cook, stirring frequently, until starting to soften, 1 to 2 minutes. Add greens, garlic, salt and pepper; cook, stirring often, until very soft, 10 to 20 minutes, adding water 1/4 cup at a time if the greens start to stick. Sprinkle with flour and cook, stirring, for 30 seconds. Stir in milk and nutmeg (if using); cook, stirring, until just starting to boil and thicken, 1 to 2 minutes. Serve hot.Advertisement
Trim leeks, split lengthwise and wash in plenty of water until no grit remains.
3 vegetable, 1 fat