Leftover patties are good in a sandwich for lunch the next day. This mixture also makes a good meatloaf.
This makes about 3 or 4 burgers, depending on your appetite:
Melt butter in frying pan. Slice scallions, including part of the green, and chop the mushrooms into smallish pieces. Saute for 5 minutes.
Mix everything except the rolls with the ground beef. Using your fingers in a big bowl is the best way. Shape into three or four patties.
Saute over a medium flame to desired doneness or broil. Serve on toasted rolls.