Go Fish

Has this ever happened to you? You're standing at the fish counter, waiting for your purchase to be weighed, but when the fishmonger slaps your piece on the scale, you think - but don't say - that the fillet looks too thin, or too long, or somehow not quite right. At home, the taste is fine, but the fish itself looks insignificant on the plate. Remembering the voluptuous fish you had the other night at a restaurant, your own home-cooked entree seems disappointing.

Consumers need to be persnickety. Rather than settling for a thin tail end, order the same thick cuts that restaurants get. Tuna, for instance, is generally sliced too thin, so that when you divide a steak into 4 servings, they look paltry. Cut thicker (more than 1 inch thick), that tuna sits on the plate looking practically regal.

There is no need to be intimidated. Buying fish isn't much different from buying a head of lettuce. If you can't find what you want on top of the lettuce pile, you pick through it until you find one with bright green leaves. Obviously, you can't pick through a tray of haddock fillets, but you can ask the fishmonger to check his case for thick cuts that satisfy you. In your own kitchen, open the freshly wrapped package, and you'll love what you see. Sear the fish in a very hot skillet, finish cooking it in the oven with vegetables and potatoes, and you're on your way to acting like a pro.

HOW TO ORDER FISH

The thin end of the fillet is the tail. If you want 4 thick pieces of salmon, ask the fish-monger to give you a cut from the head end of 2 different fillets. When you get home, cut each one in half, and you'll have the thickness you want for all 4 pieces. You can buy thickly cut tuna as well, but the piece you want may not be on display in the fish case. Don't hesitate to ask for an order cut to your liking. When buying cod, ask for the very thick piece that sits near the head end. (The fish becomes quite thin near the tail.) Halibut commonly comes as a bone-in steak (a fine cut for broiling), but it's also available as fillets. Again, the pieces near the head are much thicker. If you buy a whole fillet of haddock, be sure that when you cut the fish into portions, you leave the tail end twice as large as a piece from the head end. Fold the tail piece in half with the skinned sides facing. That piece will be almost as thick as the others - and it will cook in the same amount of time.

SEARING TECHNIQUES

The recipes on this and the facing page begin by searing the fish in a heavy skillet. Admittedly, this makes a mess on the stove, but it turns the outside edges of the fish appealingly crusty. Then the fish is transferred in its skillet to a hot oven so it finishes cooking without drying out. If you prefer to do the browning under a broiler, you can adapt the recipe: Brush the fish with oil and broil it close to the element for 2 minutes on a side. Then turn the oven to the temperature called for in the recipe and slide the skillet to an oven shelf at least 12 inches from the hot broiling element. Continue cooking the fish as directed. If you are grilling, first sear the fish over the hottest part of the grill, leaving it there only until the outside is browned, then transfer the fish to a cooler part of the grill to finish cooking.

TUNA AU POIVRE WITH GREEN BEANS AND POTATOES
SERVES 4

Crack peppercorns by placing them between several layers of paper towels and forming them into a bundle. With a cast-iron skillet, pound the peppercorns until they are coarsely cracked. Use kosher or sea salt for this dish.

Salt, to taste
1 pound haricots verts or other slender green beans
8 small red potatoes
1 3/4 -pound piece tuna, cut at least 1 inch thick
2 tablespoons cracked peppercorns
5 tablespoons olive oil
Freshly ground black pepper, to taste
1/4 red onion, thinly sliced
Leaves from 3 stalks flat-leaf parsley
1 tablespoon red wine vinegar

Bring a large saucepan of water to a boil. Add a pinch of salt and drop in the beans. Let the water return to a boil. Cook the beans for 2 minutes or until they are cooked through but still bright green.

Tip the beans into a colander and rinse them with cold water until they are cold. Set them aside.

Fit a steamer insert into the saucepan and fill the pan with water up to the level of the steamer. Place the whole potatoes in the steamer, cover the pan, and bring the water to a boil. Turn the heat to medium-high and steam the potatoes for 10 to 15 minutes or until they are tender when pierced with a skewer. Transfer the potatoes to a plate to cool.

Set the oven at 450 degrees. Have on hand a cast-iron or other heavy-based skillet with a heatproof handle.

Cut the tuna into 4 even-sized pieces. Rub them with salt and cracked peppercorns, pressing them into the flesh.

Heat the skillet until it is quite hot. Add 1 tablespoon of the oil. Add the tuna pieces in 1 layer. Sear them for about 2 minutes on a side. Turn the tuna only when it releases easily from the bottom of the pan.

Transfer the skillet to the oven and cook the fish for 4 to 5 minutes more or until it is cooked through but still pink in the center.

Halve the potatoes and cut them into 1/4-inch-thick rounds. Heat another large skillet. Add 3 tablespoons of the oil. When it is hot, add the potatoes, salt, and ground pepper. Cook over medium heat for 5 minutes, turning them often, until the potatoes are crisp.

In a bowl, combine the haricots verts or green beans, onion, and parsley leaves. Sprinkle with the remaining tablespoon of oil, vinegar, salt, and ground pepper. Add the potatoes. Toss gently but thoroughly.

Set a piece of tuna on each of 4 dinner plates. Add potatoes and green beans and serve at once.

HALIBUT WRAPPED IN PROSCIUTTO
SERVES 4

At the South End's Caffe Umbria, chef Laura Brennan wraps a thick, square piece of halibut with Italian prosciutto. She begins by cooking the fish in a hot skillet, then finishes it in the oven. The apple-and-leek garnish enriched with heavy cream served with the dish is a kind of stove-top gratin.

2 tablespoons butter
4 small leeks, white part only, halved and thinly sliced
Salt and pepper, to taste
4 Granny Smith apples, peeled, cored, and thinly sliced
1/4 cup heavy cream
1 3/4 pounds boneless halibut, cut at least 1 inch thick
8 slices prosciutto
1 tablespoon olive oil

In a skillet, melt the butter. Add the leeks, salt, and pepper and cook over medium-low heat for 10 minutes, stirring often, or until the leeks are tender. Stir in the apples, cover the pan, and continue cooking, stirring occasionally, for 20 minutes or until the apples are tender.

Pour the cream into the pan at the edges. Stir well and set the pan aside, off the heat.

Set the oven at 350 degrees.

Cut the halibut into 4 even-sized pieces. Sprinkle them with salt and pepper. Wrap 2 pieces of prosciutto around each piece of fish, securing it at the sides with toothpicks, or tie the fish with string.

Have on hand a cast-iron or other heavy-based skillet with a heatproof handle. Add the oil. When the oil is hot, add the fish in 1 layer. Sear it for about 2 minutes on a side. Turn the fish only when it releases easily from the bottom of the pan.

Transfer the skillet to the oven and cook the fish for 10 minutes more or until it springs back when pressed gently with a fingertip.

Meanwhile, stir the apple mixture over medium-high heat until it is hot and the cream is absorbed by the fruit.

Divide the apple mixture among 4 dinner plates. Top with the fish. Remove the toothpicks or string and serve at once.

Ask the Cooks: Sweet Stuff

What is the best way to make caramelized onions, and what types of onions are best for caramelizing?
Barbara Gerber /// Dorchester

You've asked about onions just as they are coming into season. Yes, they have a season. You might see stacks of yellow onions in produce bins year-round, but in spring, another, sweeter variety is harvested from warm- weather states. These are the best ones to caramelize. Caramelizing, for those cooks new to this wonderful technique, is the process of cooking sliced or chopped onions very slowly in a little butter or oil until the onions are translucent, almost melted. That may take 40 to 50 minutes. The onion juices evaporate in the skillet and turn the mixture into a panful of candylike goodness. You can spread caramelized onions on toasted French bread rounds to serve with wine before dinner or use them as a garnish with roast chicken or a thick chop.

Sweet varieties are mostly large and include Vidalia, named for the Georgia town where the onions were first harvested 60 years ago. Vidalia has a big marketing machine behind it. What many consumers don't know is that there are other sweet kinds, including Texas 1015s (they take their name from their October planting date); Walla Wallas, originally from Italian seeds (grown in Washington state and Oregon); Sweet Imperials (California); Mauis (Hawaii); and OSO Sweets (Chile). Unlike regular onions, the sweets tend to be perishable. We store them in the refrigerator and make what we call "onion jam" all spring and summer.