A "grain bun" refers to a type of bread roll that is made with grains, such as wheat, oats, or barley, instead of just plain white flour. Full definition
My first attempt is this sweet potato lentil burger that I served on my homemade whole grain buns with guacamole, arugula, and tomato slices. (reciperebuild.com)
* Buy whole - grain buns for the burgers and just use a couple of them to grind in the food processor for the crumbs that you'll need. (recipegirl.com)
-LSB-...] sure you use a whole grain bun instead of a highly processed, white one. (easypeasylifematters.com)