Preheat oven to 210°C or barbecue to medium/hot.
Bring the Beef to room temperature.

Season the Fillet with crushed Garlic, Salt and Pepper. Fold the Pancetta around the meat, starting at one end and ending at the other so that the meat is now encased in a Pancetta blanket.  With cooking string, tie the whole piece of meat at 1 cm intervals, ensuring that you tuck the thin tail of the fillet around to the middle of the meat to make an even log.  Heat a lightly oiled frying pan and quickly brown meat on all sides. Put Beef fillet into a roasting pan and drizzle with Olive Oil.  Roast in the oven for 20 minutes for a medium-rare fillet.

If barbecuing, use a dutch oven or cast iron deep frypan with an oven proof lid.
Carefully monitor the meat for temperature and remove and plate up covered in foil afterwards to avoid the meat overcooking in the cast iron.

Remove from oven and leave to stand for 15 minutes in a warm place (covered in foil) ensuring that you collect the meat juices. 
Make a jus by combining the meat juices with the beef jus and 1/2 cup Red wine.  Season with Salt and Pepper and reduce.
Slice Beef and serve with potato gratin, sautéed peppers, field mushrooms and Bearnaise Sauce.
Spoon jus over beef and serve!

MAKING THE BEARNAISE SAUCE
There is no easy way out of this!  You have to make this sauce on the spot by hand if you want the best flavours!
Combine Vinegar, White Wine, onion and herbs with Salt and Pepper in a saucepan and bring to the boil reducing the mixture by half.
Beat Egg yolks and then add wine mixture into the egg beating fast to prevent curdling. 
Gradually add the hot melted butter, beating until thick.
Return to saucepan and beat for 1 minute over moderate heat. 
Taste test and if required add extra seasoning and/or some lemon juice beating as you do!
You can add the meat juices from the standing dish at this point.