Season the steak with salt and pepper. Core, top and tail the vegetables and cut the peppers and onion into eights, slice the aubergine and courgette into thickish strips and halve the mushrooms, if large. Place them all in a large bowl and drizzle generously with olive oil. Preheat a frying pan and the grill with no rack on it. Place the vegetables in the hot grill pan, season with salt and pepper and cook for 20 minutes, tossing around every now and then. Meanwhile, when the frying pan is smoking hot, set the timer for 4 minutes, place the steak in the pan and flip every 15 seconds. Remove and keep in a warm place, covered loosely with foil.