Preheat oven to 210°C. Rinse the fillet and pat dry. Remove any fat and silverskin. Make a small cut in the centre of the meat at one end, then use the rounded handle of a wooden spoon to push through the meat to form a small tunnel.
Mix the ham, garlic, nutmeg, crumbs, salt and pepper together in a small bowl. Add enough egg to bind (roughly about half of it). Stuff it into the cavity, using the wooden spoon to push it in, threading in the basil as you go and adding the pistachio nuts.
Tie the beef with string in a neat shape. Heat the oil in a smallish shallow roasting tin over a medium-high. Add the beef and brown it quickly. Place in the preheated oven and cook for 15 minutes, turning it over after 7 minutes. Remove from the oven, tent with foil and rest for 10-12 minutes.
Remove the string and slice the meat evenly. Rest it for 1-2 minutes then transfer to a heated serving platter. Skim the pan juices, pour in wine and boil it briefly. Spoon the juices over and around meat. Serve immediately.