Remove the steaks from their packaging and pat them dry with kitchen paper. Rub each steak with 1 tsp olive oil and some salt and pepper. Set aside.

Finely chop the rosemary leaves and pop them in a bowl. Finely grate in the lemon zest and squeeze in the juice from half. Add the room temperature butter with a pinch of salt and pepper. Mash together using a fork and set to one side.

Pick the cherry vine tomatoes off their stems. Warm a large frying pan or wok on a mediumhigh heat for 1 min then add the cherry tomatoes. Fry for 10 mins, stirring often till the tomatoes are slightly blackened, soft and collapsing.

While the tomatoes cook, warm another frying pan on a high heat for 3-4 mins. When smoking hot, carefully add the steaks and cook them for 30 secs on each side for rare. Cook 1-2 mins on each side if you like your steak more well done, or if the steaks are on the thicker side. Lift the cooked steaks out of the pan onto a warm plate or board, cover with foil and leave to rest for a few mins. Take the pan off the heat but keep it ready – you'll need it to make the butter sauce.

Drain and rinse the butter beans. When the tomatoes have cooked for 10 mins, add the butter beans to the pan. Turn the heat down to low and cook for 2 mins, stirring, to warm them through.

Tip the butter mixture into the empty steak pan. It should still be warm. You just want to melt the butter. Swirl it in the pan then pour into a small bowl to stop it burning.

Divide the watercress between a couple of plates. Top with the tomatoes and butter beans. Thinly slice the steaks and place them on top. Spoon over the rosemary butter and serve with the remaining lemon cut into wedges for squeezing.