IT was a fine day for fish, a bad day for humans -- cold, wet and windy. After squeaking into a parking place near Grand Central Terminal, Patricio Osses jumped out of his white van and flashed a triumphant smile at Julian Alonzo, the executive chef at Cafe Centro. ''Man, I have got some ugly fish,'' he said, throwing open the back doors of the van.
He wasn't kidding. Mr. Alonzo leaned forward and, deep within the refrigerated gloom, his eyes made out the horrid forms of fish that dare not speak their names, strange creatures that haunt Chilean waters but are now, thanks to Mr. Osses, creeping onto restaurant tables in New York. In a city full of the remarkable and various fish of the world, the very strangest creatures of the deep come from this one purveyor.
Warming to his work, Mr. Osses pulled pulled out several boxes of choros zapatos, whose name, which means shoe mussels, gives an idea of their size. They easily fill the palm of one hand. Out came the limpet-like mollusks known as locos (crazies) and a crate of sea urchins that looked like large, perfectly formed divots -- but alas, no elephant fish, a large-headed specimen with a big schnoz that, when threatened, stands bolt upright and spins like a dervish.
The good news? Picorocos, and lots of them -- enormous barnacles, nearly a foot tall, with a surprise inside their volcano-like shells.
''These guys are alive and kicking,'' Mr. Osses said. ''They're moving.'' He gently pushed a finger into the quarter-size opening at the top of a shell. Inside, a heaving, fleshy mass with a thick, ribbed skin began to stir. Enraged, it heaved upward, extending two clawlike fingers and, in slow motion, lunged at the alien finger.
Mr. Alonzo picked up a plastic bag filled with what looked like small roasted red bell peppers and took a sniff. They were piures, a kind of sea squirt. ''I worked at the Sea Grill for five years,'' Mr. Alonzo said, ''but this guy brings stuff I've never seen before in my life.''
That's the point.
Mr. Osses, 33, a Chilean, survives by offering chefs the kind of fish they cannot get anywhere else. Over the last 10 years, he has built up his business slowly, selling door to door, opening up his van and bringing out boxes of fish that make chefs stop and scratch their heads.
In the early days, he was lucky to sell 600 pounds of fish a week. A few weeks ago, achieving a personal best, he moved more than 10 times that amount. That's still small volume, but in the weird-fish market, Mr. Osses is the man. ''He brings me things that make my mind wander,'' said Rick Moonen, the executive chef at Oceana. ''He makes you realize that there's a whole other world out there.''
That other world lies just off Chile's seemingly endless coastline, where small fishing boats head out each morning from Valparaiso and return the same day with sea bass, whiting and congrio, as well as dozens of other species unknown to most North Americans.
Mr. Osses's father, Rudy, meets the boats. What he likes, he buys. Within 24 hours, the fish is on an airplane bound for New York and into the waiting arms of his son, who loads it onto his refrigerated van, painted with the name of his company, Pacifica International, of Rego Park, Queens.
Fish is not exactly in the Osses family blood. ''To be honest, I never even tried fish before I came to New York,'' Mr. Osses said. ''I'm from Santiago, which is inland. When my father would take us to the seashore, I'd order steak and potatoes.''
Fate, however, threw a couple of curves at Mr. Osses. First, his parents divorced, and he was taken by his mother to Rotterdam, where he attended school, learned Dutch and English, and planned on a career in language studies.
After finishing college, however, he rejoined his father, who had moved to New York and had started a wholesale fish business, betting that the glorious Merluccius australis, Chile's version of the whiting or hake, so beloved in Spain, would make his fortune. It didn't. Burned by deadbeat creditors, the elder Mr. Osses returned to Chile, but his son saw a business opportunity in Chilean fish, if it was done on a small scale. He installed his father and his uncle Juvenal in Vina del Mar, a coastal town near Valparaiso, and began importing whiting, Chilean sea bass and congrio.
He caught a lucky break when Solera, a Spanish restaurant in midtown, took a fancy to his fish, especially the whiting, a tender, sweet-fleshed fish that is the starting point for one of Spain's classic dishes, merluza con salsa verde, whiting in a parsley-garlic sauce. The Chilean merluza is sometimes sold under the name Antarctic queen.
Rufino Lopez, the owner of Solera, remains a good customer. He has a roving palate, and if he sees anything odd in the white truck, he wants to try it out. ''With these picorocos, all I have to do is make a few phone calls, and they're sold,'' he said, grabbing a dozen that he would later bake for about 25 minutes in the oven and then serve as is, a rich lump of white flesh swimming in its own fragrant broth. ''The top part is almost like the claw of a lobster. The middle part is somewhere between skate and crab, and the bottom part is like a big oyster.'' In Chile, the picoroco is added to sauces or to fish soups. Mr. Osses is pushing the picorocos, sensing a trend in the making, but his best volume sellers are sea bass and, more recently, the whiting, which he has been supplying to the Fulton Fish Market and to customers in Puerto Rico. Some of his fish also ends up at Wild Edibles on Elizabeth Street. After a stop at Oceana, Mr. Osses was done with Manhattan. He headed out to Queens, where he delivered congrio to two Chilean restaurants, El Arrayan (The Bush) and La Gaviota (The Seagull). At both places they will be served the traditional Chilean way, deep-fried without any fuss. The flesh is firm and rich, with a scalloplike flavor. ''In Chile, it's like our flag,'' Mr. Osses said. At Cafe Centro, Mr. Alonzo gave the congrio an Asian treatment, cooking it in a Chinese black bean broth flavored with garlic, ginger, lemongrass, sake and Indonesian soy sauce. The locos are another matter. This ovoid mollusk, which fits neatly into the palm of one hand, needs serious tenderizing. One method is to put it into an inner tube and beat it against rocks. After an enthusiastic beating and 25 minutes of boiling, it comes out as soft as a potato, which is, in fact, the traditional accompaniment to the loco, which is served on a bed of shredded lettuce with a dollop of mayonnaise and a squirt of lemon. It tastes like a cross between a lobster and a sea bass. ''You have to be careful cooking them,'' Mr. Osses said. ''If you don't do it right, you can bounce them off the walls.'' Piures may be the ultimate test of dinerly nerve. In the wild, they look like seaweed-covered potatoes. Once the shell is removed, a soft, red-orange body emerges, with a pungent smell of brine and iodine. In Chile, the piure is marinated briefly in lemon and then added, sparingly, to a platter of ceviche.
A day after accepting a bag of sea squirts, Mr. Alonzo of Cafe Centro was still trying to crack the code. ''I tried those little red things,'' he said. ''They have a weird texture and flavor. Very interesting, but not easy to come up with something -- they're chewy when you cook them, and very smoky tasting.'' In New York, a city that lives for adventure, it just might work if presented as a new dining concept: the abuse-bouche. STEAMED ELEPHANT FISH WITH GINGER AND CHINESE BLACK BEAN BROTH Adapted from Julian Alonzo of Cafe Centro Time: 30 minutes 5 tablespoons unsalted butter 2 tablespoons minced garlic 2 tablespoons minced ginger 2 tablespoons minced lemongrass 1 tablespoon fermented Chinese black beans, rinsed and coarsely chopped 1 cup sake 1 cup chicken stock 1 tablespoon soy sauce 1 tablespoon rice vinegar 1 tablespoon kejup manis (Indonesian soy sauce), if desired 4 elephant fish fillets (preferably freshly cut from small whole fish), 6 to 7 ounces each, skin removed, or 4 fillets Chilean sea bass
Salt 1 piece ginger, about 1 1/2 inches long, peeled and julienned 2 teaspoons extra virgin olive oil 1 garlic clove, peeled and thinly sliced 8 ounces fresh spinach leaves, washed and dried 1/4 cup thinly sliced scallions, for garnish 1 cup fresh bean sprouts, for garnish. 1. In a small nonreactive saucepan over medium-low heat, melt 1 tablespoon butter. Add minced garlic, chopped ginger, lemongrass and black beans. Saute until softened and garlic is translucent, about 3 minutes. 2. Add sake and stock, and mix well. Increase heat to medium-high, and boil until reduced by two-thirds, about 10 minutes. Remove from heat, and whisk in soy sauce, vinegar and kejup manis. Set aside, and keep warm. 3. Season fillets with salt. Place a bamboo steamer over simmering water, or set a rack or heat-proof plate over simmering water in a covered wok. Add fillets and cover each with an equal amount of julienned ginger. Place 1 tablespoon butter on each. Cover, and steam until fish is opaque and ginger is softened, about 4 minutes. 4. Meanwhile, place a large saute pan over medium-high heat. Add olive oil and garlic, and saute until garlic begins to sizzle but not color. Add spinach, and saute until wilted. 5. To serve, distribute spinach among four plates. Place a fillet on top, and spoon broth liberally over. Garnish with scallions and bean sprouts.
Yield: 4 servings.
A version of this article appears in print on March 31, 1999 , Section F, Page 1 of the National edition with the headline: From the Seven Seas to New York Tables; His Specialty: Oddest Sea Life This Side of Loch Ness