Whizz together in a food processor or finely chop herbs, garlic and capers, and add other ingredients.
Smear over steak and leave for 1-2 hours for flavours to develop.
To make Blue Cheese Dressing: Mix together yogurt, cheese and dill, serve chilled.
Cook steaks on a preheated grill or BBQ for 3 minutes each side (for medium cook).
Serve with tomato and dill salad with a dollop of blue cheese dressing and boiled new potatoes