Browsing the shelves of City Market, Onion River Co-op's South End location, I found an object in the freezer section that gave me pause. It was an amorphous brown blob of seitan with a label that boasted, "Vermont Owned Family Business Since 1979." Thinking it would be an economical choice for quick lunches, I threw a $9.99 "pounder" in my cart. Seitan, a wheat gluten-based alternative protein sometimes called "wheat meat," evokes 1970s hippie food, unless it's masquerading as meat in a trendy, ready-made product such as fake chorizo or beef crumbles. Christina Denby has made her Sheffield Seitan in Lyndon for upwards of four decades. Her product doesn't pretend to be anything but what it is: "Organic wheat gluten, cooked in natural soy sauce, spices, and water." And the simplicity is magic. "It's unique and a step above any seitan I've ever encountered," said Tim Elliott, co-owner of Zabby & Elf's Stone Soup in Burlington. He has been cooking with Sheffield Seitan since about 1992, back when he ran the vegetarian deli at the long-gone Origanum Natural Foods on Main Street. Elliott appreciates the product's versatility, he said. It's large enough that he can cut it thin on a meat slicer before he marinates it in maple syrup and tamari and layers it on bread for the popular veggie Reuben sandwich. He also creates seitan pepper "steaks" with the slicer and runs the seitan through a cheese grater so it can mimic ground beef in specials such as Cuban stew. "It's one of those blank slates that is really great at soaking up sauces," he said. Now 74, Denby bought the business with her late husband, Leo Denby, in 1981. It has taken several forms over the years; at one point, the couple delivered wheat puffs (tempura-fried seitan) around the state while picking up and reselling fresh specialty breads such as bagels, Jewish rye and croissants. Elliott fondly remembers the days when Leo would truck his goods to Burlington, bringing a complimentary snack of cornmeal-breaded seitan that "fried up just like chicken fingers" and tasted "stupid delightful." Eventually, a New Hampshire-based distributor scooped up the seitan and scattered it across the Northeast. When that company was bought by a larger one in New Jersey, Denby severed the relationship, opting to ship frozen seitan straight from her shop in the Northeast Kingdom to individuals, retailers and restaurants, including…