Shrimp Diane

1/2 t white pepper
1/2 t cayenne pepper
1/2 t black pepper
1/2 t thyme
1 t salt
1 t garlic powder
1/2 t onion powder
6 T butter
2 1/2 lb. whole shrimp, peeled
1 cup chopped scallions
2 cups chopped mushrooms

Combine all of the spices in a bowl.  Butterfly the shrimp by
slicing along the vein half-way through.  In a large saucepan, over
medium heat, partially melt the butter.  Place the shrimp in the
pan and shake in a circular motion without untensils. Add scallions
and spices.  Cook until shrimp curl.  Add mushrooms.  Cook no longer
than 12 minute more.  Serve over brown rice.