Mushroom
Mushroom appears in 6 of the 123 recipes on Burgerman, roughly 5% of the library. In these builds it is the fresh element, and recipes here disagree about how much of it a burger can take. You will find it in French Onion Burgers, Portobello Mushroom Burgers and Mushroom Swiss Burger, among others. The highest-scoring recipe using it is French Onion Burgers at 8.5 out of 10. It turns up most often alongside black pepper, garlic, butter.
