3 porcini crusted beef tenderloin with Recipes

whole beef tenderloin , trimmed of fat, silverskin, and the chain (see cooks notes); or a 5- to 5 1/2-pound well-trimmed tenderloin roast, salt, freshly ground black pepper, olive oil, divided, dried porcini mushrooms, ground to a powder in a blender, black-truffle butter, softened, all-purpose flour, crimini (baby bella) mushrooms, trimmed and quartered into wedges, beef stock or low-sodium broth, divided, chopped scallion greens

center-cut well-trimmed beef tenderloin roast, dried porcini mushrooms, olive oil, grated parmesan cheese, coarse grind black pepper, minced garlic