Photos, story by Cassie Hepler The James Beard Foundation is challenging restaurants and diners nationwide to reach for a better burger this summer – a blended burger – which adds at least 25 percent earth-friendly mushrooms into the patty. The Blended Burger Project kicked off on May 29 with more than 350 restaurants participating across 45 states, from fine dining to chain operators. “A ‘Blended Burger’ is a much more sustainable and plant-forward opportunity for chefs to menu the iconic burger,” said James Beard Foundation vice president Kris Moon. “We are excited to see so many restaurants of all types take part in the Blended Burger Project.” We came, we…