For the roast beef
- 225g piece fillet of beef
- ¬? tsp mustard powder
- 1 tbsp olive oil
For the Yorkshire puddings
- 2 tbsp sunflower oil
- 100g plain flour, sifted
- 2 eggs
- 175ml milk
For the horseradish cream
- 1/2 tsp English mustard
- 1 tbsp grated fresh horseradish
- 1 tsp sugar
- 1 lemon
- 75ml double cream
- sea salt and freshly ground black pepper
- fresh watercress sprigs, to garnish