Preheat the oven to 180 degrees.
Toss the potatoes in 1 tsp of the oil, then place in a large oven roasting dish. Bake in a preheated oven for 10 minutes. Meanwhile combine the pepper and salt on a dinner plate and roll beef in it to form a thin crust.
Heat the remaining oil a small pan and brown the beef on all sides to seal the crust. Remove from the heat and place in a baking pan with potatoes and cook for a further 15 minutes.
Scatter the asparagus spears and tomatoes and bake for 10 minutes more. Remove the meat from the pan and wrap in foil to rest for a few minutes. Slice beef thickly and serve at once with vegetables.