Fiddlehead ferns are the tightly curled emerging fronds of the ostrich fern (Matteuccia struthiopteris), a native of wet soils from the Great Lakes to the Atlantic Ocean and north into Canada. Whether grown in your garden, foraged from the wild or purchased at the supermarket, fiddlehead ferns are available for only about three weeks, beginning around May 1. With a little preparation, you can use fiddlehead ferns as a substitute for green beans or spinach in most casserole and quiche recipes, or in the most common New England preparation, sauteed in butter with wild leeks or garlic.
Clean the brown, papery coating from the fiddleheads by placing them in the bottom of a clean bucket, then filling the bucket with water from a hose. Allow the water to fill the bucket and run over the top, carrying the papery coating with it. Use the pressure from the hose to stir the fiddleheads until the water overflowing the top of the bucket is nearly clear of debris.
Pour excess water off of the bucket, then turn the fiddleheads out into a colander. Rinse again with the hose or in the kitchen sink, removing any remaining papery coating bits by hand and snapping off any long or broken stems. Run your thumb over the flat sides of each fiddlehead to rub off any protruding bits of leaf for a more elegant presentation. Drain well.
Fill large saucepan or small stockpot halfway with water. Add 1 tsp. of sea salt for every 2 qt. of water in the pot. Bring the water to a rolling boil.
Add fiddleheads gently to boiling salted water. Boil for 1 minute, then drain the fiddleheads through a colander. (You can now use these prepared fiddleheads in any recipe calling for greens or green beans, or proceed to saute.)
Melt butter in a large saute pan, using 1/4 cup of butter for every 2 cups of prepared fiddleheads. Add chopped wild leeks or garlic to taste, and saute until the leeks or garlic are soft.
Add the fiddleheads into the butter and leeks or garlic mixture. Saute briefly to mix flavors. Cut fresh lemon into quarters and squeeze juice onto sauteed fiddleheads to taste. Serve hot.