Deli

In a large bowl, combine bison, Worcestershire sauce, shallot, garlic, salt, pepper, coriander, and ground mustard. Form into 8 patties that are slightly larger than your hamburger buns. Let sit at room temp for 30 minutes.

In a large skillet over medium heat, melt butter. Add onions and cook, stirring occasionally, until golden, 20 minutes. Remove from skillet and place on a plate and tent with foil to keep warm.