A new cookbook called “The Book of Lost Recipes” remembers classic dishes from long-gone hotels, iconic restaurants and roadside eateries of yesteryear. A recurring theme in the book, out this month from Page Street Publishing, is how immigrant chefs took ethnic food mainstream. Other dishes in the book were beloved by regular folk, such as chicken soup and mac-and-cheese from Horn & Hardart’s, the famed automat. […] how a dude ranch in Tucson, Ariz., opened an upscale restaurant called The Tack Room so that its guests – who came to Arizona to escape cold weather – could enjoy fancy meals such as veal with chanterelle mushrooms after a long day of riding horses. Saxena not only pored over old guidebooks to see what restaurants were recommended as worthwhile for diners to seek out on their travels, but she tracked down descendants of chefs and restaurant owners to get their stories. […] other dishes would be right at home in any hipster cafe in Brooklyn, such as bratwurst and sweet-and-sour lentils, created by a German immigrant, Henry Thiele, a famous restaurateur in the Pacific Northwest who was admired by none other than a young James Beard. Whisk together the flour, water and salt, and grease the pan lightly with vegetable oil or butter, using a towel to apply so all corners of the pan are covered. Remove blintzes to a paper towel to drain and place on a heated serving platter.