preheat oven to 400°...
heat large skillet. season beef with salt and pepper, going heavy on the pepper. heat oil.
sear beef until browned, about 8 minutes. transfer to roasting pan. roast about 30 minuted until internal temperature is 125°
place roast on cutting board and loosely tent with tin foil.
to same skillet add mushrooms, scallion whites, garlic, ginger, 1 1/2 t salt and pepper flakes. cook until soft, 8 mins. add scallion greens and sherry and cook until liquid evaporates, about 2 minutes.
slice roast, serve with veggies