Melt butter in a skillet. While foaming is subsiding, lightly dredge roe in flour and shake off excess. Add roe and cook until lightly browned, about 4 minutes. Turn over, and brown on the other side. Remove the roe to a plate. If necessary add more butter to the skillet. Add ginger and saute for a moment. Add lemon juice and remove from heat; season with salt and pepper, add parsley or chives and spoon over shad. Serve with lemon or lime wedges.