Mallmann was raised 200 miles south of Mendoza, in the town of Bariloche, the Aspen/Jackson Hole of Argentina. His father, a physicist, had moved the family there when he set up Argentina's atomic energy program (a pursuit he later abandoned in favor of sociology). Like many members of the upper—or at least well-educated—class, young Mallmann attended an Argentine version of an English public school: veddy British, right down to the short pants and blazers.

At age 11 he had an epiphany. "These three lovely Australian girls showed up at my school. They invited me over for tea and put on a Monkees record. We started dancing on top of the table. Then they put on the Grateful Dead, Black Sabbath, Jimi Hendrix. That day my life changed. I got a guitar and started singing in bars. I grew my hair long, stayed out late, lost interest in school. When I was sixteen, my dad signed my emancipados [legal papers that release a child from parental oversight]. I bought a cheap ticket and flew to America."

He spent the next two years in California, going to Grateful Dead concerts, busking on the streets of San Francisco, working in a day-care center, auditing classes at a nearby college, and hanging out in a beautiful house overlooking the ocean in Santa Barbara. It was heavenly, to hear him tell it, but not a way to spend the rest of his life.

Mallmann returned home, where he had an offer from a woman friend in Bariloche who had been to Le Cordon Bleu in Paris. She invited the young man, who was a good home cook, to join her in a restaurant venture. This was in late 1975. Shortly before the restaurant was slated to open, the woman announced that she was going to India for a month.

She didn't come back, but her father, who was the principal backer, liked Francis and was understandably interested in recouping his investment. Nahuel-Malal (a local Native American name meaning Little Hill of the Jaguar) opened, serving a table d'hôte menu. To build a clientele, the dashing young chef would hang out at the ski slopes all day, chatting up people on the lift lines and taking reservations for that evening.

Nahuel-Malal attracted notice, and restaurateurs began seeking out Mallmann for his potential star power. In 1979, a Uruguayan family asked him to open a seaside restaurant in the village of José Ignacio, about 40 miles up the coast from fashionable Punta del Este. At the time, the little village by the lighthouse was an out-of-the-way beach town. Today, thanks largely to the following Mallmann developed there—first at La Posada del Mar and then at his own restaurant, Los Negros—it is still a simple village and yet a chic one, with modest beach houses renting for $50,000 a month in season.

The Uruguayan restaurants were moneymakers. Better still, they were open only three months a year. That left Mallmann another nine months to fulfill his dream of cooking in France. "There were 23 three-star restaurants in the Michelin guide," he said. "I wrote to all of them asking for a stagier [internship], and they all said no." However, the chef at a two-star restaurant, Ledoyen, told the eager Argentine that he would be welcome.