

Heat the olive oil in a frying pan. Add the onion and season. Cook on a medium heat for 10-15 minutes until golden and caramelised.
Season the steaks well then bbq or griddle (chargrill) for 2-3 minutes each side for rare or medium, then rest for 10 minutes.
Mix together the creme fraiche, horseradish, lemon juice and season. Slice the meat about 1 cm thick. Fill each roll with steak, watercress, onions and horseradish cream and serve.
Serves 8.