"I was stuck without a local source for yeast. So I found local apple cider, fermented it, and made my own sourdough starter," said Hart. "This is not just an esoteric exercise -- I want to make a terrific meal with what's available right here in our backyard."

Hart is one of 190 chefs participating in the September 29th "Eat Local Challenge." Palo Alto-based Bon Appetit Management Company, the national food service provider which runs all of the restaurants, launched the challenge to raise awareness about where the food on our plates comes from.

On Eat Local Challenge day 150,000 diners at corporate, university, and museum restaurants from Seattle to Washington D.C. can choose to eat a 100 percent locally grown meal, made entirely of ingredients from within 150 miles of the kitchen where they are served.