beef filet with truffle mayonnaise

For somthing really special ,freshly shaved truffle makes a decadent addition to this classic roast beef
beef filet with truffle mayonnaise
Serves 6-8

1/2 cup (80ml)olive oil
1kg centre-cut beef eye fillet, trimmed
1/2 bunch thyme, leaves picked
3 onions, thickly sliced into rings
1 small fresh truffle‘ Ioptionall
1 cup (300g)whole-egg mayonnaise
3 tsp truffle oil* Micro herbs*, to serve
1 bunch watercress, sprigs picked

Preheat the oven to 200°C. Heat 2 tbs oil in a frypan over medium—high heat. Season the beef, then cook, turning, for 4-5 minutes until sealed on allsides. Transfer to a roasting pan and scatter vvith thyme. Roast for 15 minutes for rare. Rest, loosely covered with foil, for 10 minutes. Meanwhile, heat remaining 2 tbs oil in a frypan over high heat. Add onion rings and cook for 2-3 minutes until golden. Turn, season, then reduce the heat to low. Cover and cook onion rings for a further 10 minutes until just tender: Remove from the heat, then stand, covered, for 10 minutes. If using, grate 1 tsp fresh truffle, into the mayonnaise, stirring to combine.

   Alternatively, replace the fresh truffle with 2 tsp truffle oil. Set aside. Thickly slice the beef and arrange on a platter Brush the beef slices with 1 1/2 tsp truffle oil, then shave remaining fresh truffle using a vegetable peeler or mandoline and scatter over the beef with the micro herbs. Drizzle beef with remaining 1 1/2 tsp truffle oil, then serve with the onion rings, watercress and truffle mayonnaise. * Fresh truffles are available in season from growers and gourmet food shops,for stockists, visit: trufflegrovvers.com.au. Truffle oil is from gourmet food shops. Micro herbs are available from selected greengrocers and farmers markets.