For the beef:
- 2kg middle-cut thick fillet of beef
- salt and pepper
- 2 tbsp olive oil
For the sauce:
- 2 whole heads garlic
- 150ml/¼ pint mayonnaise
- 150ml/¼ pint full fat crème fraîche
- ½ tsp sugar
- 2 tbsp wholegrain mustard
- Preheat the oven to 220°C/Gas 7 (fan 200°C).
- Rub the fillet of beef with plenty of salt and pepper and the oil.
- Heat a large frying pan until very hot. Fry the fillet on all sides until browned. Transfer to a roasting tin.
- Place the fillet in the centre of the roasting tin, arrange the whole garlic bulbs around the fillet and drizzle with a little oil. Roast for 23 minutes for medium-rare (only 20 minutes if it is a long, thin piece).
- When the beef is cooked, remove from the oven, cover with aluminium foil and leave to rest for 15 minutes.