It's time for shad, sorrel, and fiddlehead greens

Although supermarkets provide us with strawberries in winter and lobsters miles away from the ocean, there are a few very special seasonal foods that are available only for a short time in the spring, and now is the time.

Along with rhubarb and asparagus, three of the other signs of spring are fiddlehead greens, shad, and sorrel. All require searching, and when you do find a market that will have these delicacies, it often takes several trips to hit the day when they are in the store.

The shad start their spawning season up the Atlantic coast from northern Florida in late December. Beginning in February they are caught in Carolina waters, and later on farther up the coast as they begin to enter the major Eastern river systems to spawn. In the northeast, they are usually in the markets from late March through April and May.

Eastern transplants are caught on the West coast from early January, when the first of the Southern catch arrives, until May through June when the northernmost supply is at its height.

So if shad are heading upriver anywhere near you, or are making their way to your supermarket, treat yourself to fresh roe for a perfect springtime dinner. These fish, like salmon, migrate thousands of miles in the ocean so they can return to the freshwater streams in which they were born.

Shad itself has such intricate bone sturcture that boned fillets are usually a must. A stuffed baked shad, however, is considered by many to be such a treat that it is worth the trouble. The roe, although not popular in France, is probably more popular in the United States than the fish which the French serve stuffed with sorrel or on a bed of sorrel puree.

It took only one famous French dish using sorrel to start the current revival of this herb. Poached Salmon in Sorrel Sauce from the three-star Troisgros brothers' restaurant in Roanne started its popularity in the United States a few years ago during the beginning of the nouvelle cuisine days.

A perfect foil for fish, especially salmon and eel, it is also good with eggs , chicken, and veal. It is used in salads, a classic French soup called Germiny , and in Schav, a soup of Polish, Russian, and Jewish origins. A member of the buckwheat family and a relative of rhubarb, sorrel is a pungent green with an arrow shaped leaf that looks something like spinach. It is tangy, is often called "sour grass," and it has a lemony taste.

Although it grows wild, it is easy to grow in a home garden and comes up every year, very early in the spring. It is plentiful in my New England garden by the first of April, but for some reason it doesn't appear in the markets until June, then is available all summer through September.

Pureed sorrel has many uses, making it one of the most valuable sorrel recipes. It can be used for soup with the addition of chicken stock. It can be served warm or cold under a bed of salmon, fillet of sole, or other fish. It is algo good as a sauce over poached or hard-cooked eggs or veal scallops. It can be a filling for omelets or tarts or folded into a souffle.

Fiddlehead greens, the green, curled, new shoots of the ostrich fern, are in the market only a short time. By the time some people get out in the spring to where they might find them, they've grown into full, leafy ferns. These greens taste somewhat like asparagus, some say like green beans. They grow in the Eastern states, Iowa, Missouri, and all of Canada.

In Canada the choice is to serve fiddleheads with Atlantic salmon. Some cooks prefer to serve them with hollandaise or egg suace, but many like the greens steamed or boiled and served with melted butter and lemon juice.

They also good cooked, cold and marinated in a Sauce Vinaigrette.

Here are some recipes for these springs specialties. Sorrel Puree 1 pound fresh sorrel leaves 2 tablespoons butter 1/2 cup heavy cream 2 eggs, lightly beaten

Carefully wash and dry sorrel and remove and discard any tough ribs or stems. OVer medium heat, without adding liquid, cook sorrel just until it wilts. Remove, drain off any liquid and chop finely.

In medium saucepan, combine butter, wilted sorrel, cream and eggs. cook just until mixture thickens. Do not overcook or sorrel will lose its sharp, fresh flavor.

Use warm or cold as a bed of greens for sole or salmon or over eggs. French tarragon mustard may be added for a sharper flavor. A delicious tomato and sorrel soup can be made by adding 1 pound peeled and chopped fresh tomatoes. Buttered Fiddlehead Greens

Clean off any brown, papery sheaths that may be still attached to the greens. Rinse in several changes of cold water and cut off any ends that have turned brown.

Steam in a steamer about 20 minutes or put in quickly boiling salted water and cook over low heat until a sharp fork will pierce the stems, not too easily, about 8 to 10 minutes.

Drain and serve with hot melted sweet butter, cheese, or Hollandaise. Shad Roe 2 pair shad roe 6 ounces butter (3/4 cup) 3 to 4 tablespoons chopped parsley Salt to taste Lemon wedges

Wash roe and remove any veins being careful not to break membrane. Let stand in ice cold water for 5 to 10 minutes to firm it. Drain and dry.

Melt butter in a covered skillet. When butter is melted and warm, not hot, dip roe in it and arrange in pan. Cover and simmer over low heat about 12 to 15 minutes, turning once. Season to taste with salt, pepper, and chopped parsley. Serve with lemon wedges and butter from the pan.

Boiled potatoes and crisp bacon can accompany the shad roe. When cooking the roe, care must be taken that it doesn't become dry and tasteless. If it is sauteed, gentle parboiling for 5 minutes is a good idea as it cooks the outer membrane and prevents the eggs from breaking through.

After parboiling, let roe cool somewhat, then dredge in seasoned flour and saute in butter over gentle heat 4 or 5 minutes on each side. Pour any butter left in the pan over the roe and serve with lemon wedges. Parboiling is not necessary for baking or broiling, but the roe may be brushed and basted well with butter. Shad Roe En Papillotte 6 slices bacon 6 pair shad roe 1/2 cup butter, melted Salt and popper to taste 1/2 cup chopped parsley

Partially cook bacon. Cut 6 pieces cooking parchment in heart shapes from squares about 9 by 11 inches and butter them. Place a piece of shad roe on one side of each parchment, brush well with butter, season to taste with salt, pepper, and parsley.

Top with a rasher of bacon. Fold parchment over this and crimp edges together, making airtight packages. Bake on buttered pn at 400 degrees F. for 15 to 20 minutes, or until paper is brown and puffy. Potage Germiny (Sorrel Soup) 1 pound fresh sorrel 1/4 cup butter 1/2 cup chopped onion 3 cups fresh or canned chicken broth 2 large egg yolks 1 cup heavy cream 1/8 teaspoon freshely grated nutmeg. Salt and freshly ground black pepper

Remove and discard tough stems of sorrel. Wash and rinse well. Shred sorrel by rolling a few leaves, then slicing with a sharp knife. The shredded leaves are called chiffonade. There should be about 5 cups.

In a large saucepan heat butter, add onins, and cook until translucent and soft. Add sorrel and cook until wilted. Add broth and bring to a boil. Simmer a few minutes.

Beat yolks and add cream, stirring to blend. Add yolk and cream mixture to soup, stirring rapidly with a wire whisk. Bring just to the boil, but do not boil or eggs will curdle.

Add seasonings and serve very hot or chill and serve very cold. Some people add 1/8 teaspoon Tabasco instead of nutmeg. Serves 6.