Cube 1 1/2 cups Jerusalem artichokes or cube 2 Irish potatoes. Chop tops and bulbs of several wild onions or 1 small onion. Cook in a little water until tender. Add 1 quart milk, 1 tablespoon butter, and salt and pepper to taste. Add 1 handful of sheep sorrel or wood sorrel leaves. Serve at once and enjoy the unique flavor.