To make the parsley butter, place the butter, parsley, garlic, salt and pepper in a bowl and stir with a fork to combine. Set aside.
Heat a large non-stick frying pan over medium heat. Brush the lamb with oil and cook, in batches, for 3–4 minutes each side for medium-rare or until cooked to your liking. Set aside and keep warm.
Place the sugar snaps and beans in a saucepan of boiling salted water and cook for 2 minutes. Drain and place in a bowl with the spinach and half the parsley butter and toss to coat. Arrange on plates with the lamb cutlets and drizzle with remaining parsley butter to serve. Serves 4.