50g/2oz unsalted butter
1 large shallot, peeled and finely chopped
1 large bunch of mixed green leaves, such as baby spinach, rocket or escarole
1 tbsp sherry vinegar (or red-wine vinegar)
Sea salt and plenty of ground black pepper
12 slices of prosciutto, finely sliced
Place a small, non-stick pan over a low heat. When warm, add the butter and let it melt. Add the shallots and sweat until translucent.
Tear up the greens and add until they begin to wilt – this will not take long.
Add the vinegar, salt and pepper. When the leaves are soft but still vibrant in colour, add the prosciutto.
Toss and divide between four plates. Serve with thick slices of bread to mop up the juices.