How to Make It
In a bowl, mix the porcini powder, sugar, salt, black pepper, red pepper, garlic and olive oil. Rub the paste all over the steak. Cover and refrigerate for 12 hours or overnight. Scrape off the excess paste; let the steak stand at room temperature for 1 hour.
Light a grill, or heat a grill pan and preheat the oven to 450°. Grill the steak over medium heat for about 25 minutes per side, until crusty and brown and an instant-read thermometer inserted in the center registers 125° for medium-rare. Alternatively, brown the steak in a grill pan over moderately high heat, about 12 minutes per side, then roast in the oven for about 40 minutes. Let the steak stand for 15 minutes.
Slice the meat across the grain, drizzle lightly with balsamic vinegar and serve with an arugula salad.