By Peggy Brawley
June 09, 1986 12:00 PM

It’s Saturday night and Joanna Pruess is getting ready for a dinner party. The pink tulips and impatiens are artfully arranged in gleaming bowls, the rose tablecloth and napkins and fuchsia candles are ready to be set out. Suddenly Pruess bolts from the kitchen. Turning left at a display rack of Golden Dipt Batter ($1.59 a box), she passes a fish counter(cleaned squid, $3.99 a pound) and heads for the cheese unit of Kings Super Market in Short Hills, N.J. “I had already picked up the cheese, arugula and radicchio for the salad ” she says “but I wanted another log of chèvre to show the class what the wrapper looked like.”

A supermarket may seem like an odd venue for a dinner party, but not to Pruess, who oversees 100 such evenings a year. Actually, they are dinner parties-cum-cooking classes. Since Pruess, 42, persuaded Kings to build 900-square-foot kitchen in a former storage area in 1983, more than 11,000 students have signed up for lessons “It was the first supermarket in the country to offer a cooking school where the students get to cook, not just ob serve,” Pruess says proudly. Called Cookingstudio, Pruess’s headquarters is decorated in French-provincial prints and can accommodate up to 27 students at a time.

On this particular May night, seven couples cook dinner under Pruess’s pervision. Then they dine until after midnight (the market closes at 10 p.m. on fettuccine with asparagus, rack of lamb with carrot puree, the assembled goat cheese and lettuce salad, and a rich orange-chocolate dacquoise (a layered meringue dessert). “It was a fabulous evening,” says Carol Raskin of Morris Plains, N.J., who with husband Victor bid $400 for the class at a charity auction, then invited six couples to join them.

Pruess teaches four classes a month and oversees some 40 instructors who hold 455 classes a year. This spring’s roster has more than 100 lessons, ranging from a $5 miniclass in Maryland soft-shell crabs to An Evening in the Loire Valley featuring shad fillets with steamed sorrel ($60 a couple). Last month Pruess had Marina Maggini Tudisco of the Cordon Bleu school of Catania, Sicily, turn out gnocchi (an Italian potato dumpling) in tomato sauce. “Our doors never close,” says Joanna. “When I find someone who does vegetable sculptures and is a genius in this field, I say, This is something my students should see.’ ”

Pruess’s students also include those who can’t see. A dedicated worker with the handicapped, she has translated recipes into Braille, used Braille-marked measuring cups and has even tied a kerchief over her eyes to test preparation methods. Making the crust for an apple pie, she turned on a food processor and told pupils: “Listen for the thunk-thunk sound when the dough becomes a ball.” She also brings in an interpreter for a class for the deaf.

Although the school pulls in 4,500 students a year, Kings, a privately held, 15-store New Jersey chain ($230 million annual sales) does not turn a profit on the operation. “It enhances our image and sets us apart from the conventional supermarket,” says sales vice-president Bob Schwartz. “Working with this market is so unbelievable,” adds an appreciative Pruess with an aisle-wide smile. “Some would be terrified to buy black truffles at $320 a pound for a lesson, but Kings goes ahead And then they sell them! When I needed raspberries the produce manager flew in three flats from Chile Can you imagine that?”

Pruess grew up Joanna Rubens in Los Angeles in a well-traveled family of five children. Her father, a retired manufacturer, and mother, a former travel agent, often took their children along for sojourns in Mexico, Paris and Geneva. After earning her B.A. in English at Berkeley and a master’s at Stanford, Joanna studied 19th-century French art at the Sorbonne, free-lanced as a fashion designer in Florence and Rome, and took cooking lessons everywhere she went. “I had this fascination with Audrey Hepburn,” she recalls. “She cracked an egg with one hand [in Sabrina] and got a Prince Charming. I thought I could too.” Joanna moved to Boston and married Murray Pruess, a garment manufacturer, in 1972. Now divorced, she lives with their three children in a century-old seven-bedroom house in northern New Jersey.

Pruess came across Kings in 1982. “It was perfect,” she says. “I called up and said, ‘I could be more than a satisfied customer. I’m going to upgrade the take-out department, be a media spokesman and build a cooking school.’ ” Kings, which had offered cooking demonstrations in the ’30s, was interested. Still, reports Pruess, “it was a long nine-month courtship until they agreed to hire me.”

Now she gives seminars to store employees—like Beyond Iceberg Lettuce—which are filmed as training tapes. She looks forward to new Kings studios. “This is a wonderful time,” says Pruess, who happens to believe she has a lucky angel sitting on her shoulder. “My angel has given me fabulous opportunities, and I’ve taken advantage of them.” If the angel hasn’t brought her a Prince Charming to crack eggs for, it has, at least, produced Kings.