For the steak, place the steaks onto a clean work surface, cover with cling film and flatten with a rolling pin until 1cm/½in thick. Brush with olive oil and season with salt and freshly ground black pepper.
Heat a griddle pan and chargrill the steak for 2-3 minutes on each side, for rare meat, or longer, until cooked to your liking. Remove from the pan and set aside to rest in a warm place.
For the smoked chilli butter, place all the chilli butter ingredients into a food processor and blend until smooth. Place into a small serving dish.
For the vegetables, heat half of the butter in a frying pan and sauté the potatoes for 4-5 minutes, until golden-brown and crisp. Sprinkle over the parsley, season well with salt and freshly ground black pepper and stir.
Heat the remaining butter in another frying pan and add the mushrooms. Stir fry for 2-3 minutes until just tender, then add the purple sprouting broccoli and season, to taste, with salt and freshly ground black pepper.
To serve, divide the potatoes and vegetables equally among four serving plates. Place a steak onto each plate and top with a spoonful of smoked chilli butter.