1 pound fiddleheads, rinsed well
1/2 cup plain yogurt
1/2 cup mayonnaise
1 tablespoon lemon juice
3 teaspoons prepared Dijon mustard
3 tablespoons chopped scallions
salt and pepper, to taste
Boil or steam the fiddleheads for 5 to 10 minutes, or until tender. Drain. Whisk together remaining ingredients and serve the fiddleheads, while still hot, topped with the sauce.