4 medium King Edward or Lincolnshire potatoes, cut into 2cm/戮in cubes
1 handful fresh flatleaf parsley, roughly chopped
1 banana shallot, finely chopped
salt and freshly ground black pepper
2 tbsp olive oil
10g/陆oz unsalted butter
65g/2录oz unsalted butter
4 x 225g/8oz sirloin steaks (preferably organic), 2cm/戮in thick