the 150 years between Care me and Escoffier, the great codifiers of French cooking, French cooks had developed and named about 200 basic sauces. Add another 1,500 to 1,800 for their variations, again all with names, and the total comes to well over 2,000.

Two thousand standard sauces in French cooking and nothing to put under my salmon steaks. How could they? Did they really expect me to use a bechamel when my salmon screams for a rich brown sauce? I spent months wondering, reading everything written on sauces. Still no brown fish sauce -- no sea-worthy equivalent to the Sauce Espagnole.

Yes, there is a Sauce Genevoise, which classically accompanies salmon, but Genevoise is an Espagnole-based red-wine sauce from Bordeaux, and could hardly be called a basic brown fish sauce. So, no matter how thoroughly I checked, there it remained, the Brown Hole of French cooking. I still can't believe it.

If the sauce I wanted wasn't to be found in Western cooking, then perhaps it could be found in the Orient. I decided to look toward China. A trip to China was out of the question. I couldn't afford a trip to Paris, never mind to Peking.

However, with a little help over the telephone from Barbara Tropp, an old friend in San Francisco who knows more about Chinese cooking than anyone I have ever met, I learned that Chinese Oyster Sauce is really a concentrated brown fish stock. With that in hand, I created, along classical French lines of course, French cooking's First Basic Brown Fish Sauce.

The final chapter of French cooking is now complete. The brown hole is sealed. THE FIRST BASIC BROWN FISH SAUCE (Makes about 1 1/2 cups)

2 cups whipping cream

2 tablespoons unsalted butter

1/2 cup Chinese oyster sauce

Freshly ground black pepper

Place the cream and butter in a large heavy-bottomed saucepan and set over medium heat. Boil until cream is reduced to 1 1/4 to 1 1/3 cups. The butter will prevent the cream from boiling over, but if the heat is too high the cream will scorch, so be careful. When the cream is sufficiently reduced, turn off the heat, stir in the oyster sauce, season with pepper and it's done.

Oyster sauces, which are available in oriental and specialty markets and in some supermarkets, vary slightly from brand to brand in both viscosity and intensity of flavor. Therefore, you may want to use a tablespoon or two more or less to achieve a richly flavored sauce of the right consistency.

The finished basic brown fish sauce can be made ahead and refrigerated safely in a tightly sealed container 7 to 10 days days. Reheat over low heat to prevent scorching. BROILED SALMON STEAKS WITH BROWN SAUCE (6 servings)

6 salmon steaks

1/4 cup good quality olive oil

Salt

Pepper

1 recipe basic brown fish sauce

Rub the salmon with oil and season lightly with salt and pepper. Arrange in a single layer on a foil-lined baking sheet and broil, about 2 to 2 1/2 inches below the fully heated broiling unit, until salmon is cooked. A 1-inch thick steak will take about 10 minutes, a 3/4-inch thick steak about 7 minutes.

Spoon the sauce onto plates and top with the cooked steaks. Serve immediately. Other Uses for This Great Sauce

Combine the sauce with 2 pounds fine quality lump crab meat and half a cup each of finely chopped fresh dill and chives for a quick crab meat fricassee.

Use as a sauce under saute'ed or roasted chicken.

Combine with 1/2 cup crisp bacon pieces and 1/2 pound thinly sliced mushrooms that have been saute'ed in butter. Pour over cooked pasta and serve with grated parmesan.

Serve with any poached, baked or broiled fish that you feel needs a rich dark sauce. It is especially good with salmon, tuna, swordfish and shark.

Use as a sauce with saute'ed or steamed shrimp or lobster, perhaps topped with a garnish of julienned carrots, celery and leeks.