Heat a griddle pan or heavy based frying pan with 1 tablespoon of olive oil. Griddle the asparagus for 3 - 4 minutes, making sure that it doesn’t brown too much. Remove from the pan and reserve. Add the remaining tablespoon of olive oil and fry the steaks for 2 - 3 minutes on each side depending on how rare you like them. Remove from the pan and allow to rest for 2 minutes.
Meanwhile, mix all the horseradish dressing ingredients together then assemble the asparagus, cherry tomatoes, rocket and cucumber in piles on four serving plates. Slice the steak into five pieces and place on top of the salad, and finally spoon over the horseradish dressing and season to taste.
To reduce costs you could use rump or ribeye instead of fillet steak.