To win Rachael Ray's first on-air cooking contest, Jennifer Thomas juiced oranges at warp speed, impressed Marcia Cross with her canapés and got third graders to eat broccoli. What's more impressive: Just four years ago she couldn't stand the sights or smells in the kitchen. "I absolutely hated food," says Thomas, 25, a bartender and floral designer from Ohio, who sought treatment for anorexia nervosa six years ago. "I was convinced it was going to kill me."

At 19, Thomas says, she developed a pathological fear of getting fat—and eating any fat. "I ate a small portion of fat-free cottage cheese and pineapple tidbits maybe once a day, after a two-hour workout," she says. Friends and family noticed her dramatic weight loss and urged counseling. A year and a half of therapy helped her "work through self-esteem issues." She eventually returned to her normal weight and rediscovered a passion for cooking. "It's funny what a sense of humor God has," she says. "I love food!"

One of five finalists selected from thousands of video applications for "So You Think You Can Cook?!" "Jenn got more sure of herself as [we] went along," says Ray. "Cooking is empowering." Thomas' winnings include culinary boot camp and a spot on Ray's show Dec. 5. The real prize, though, will last longer. "I've never been 100 percent confident," says Thomas, "but I learned I can handle myself."

For Thomas' recipe for lasagna, go to PEOPLE.COM/JENNRECIPE