Place the meat between two sheets of plastic wrap and pound flat. Trim neatly.
Mix the flour, sea salt and pepper on one plate, the egg on another and the breadcrumbs on another. Coat each fillet in flour, then egg and then breadcrumb.
Melt butter with olive oil in a frying pan over medium heat and briskly fry each schnitzel on both sides until golden, adding more butter and oil as necessary.
Clean out the pan, add more olive oil and fry the eggs until the white is set but the yolk is still runny.
Top each schnitzel with a fried egg, arrange anchovies on top and scatter with sea salt and pepper.
Add the capers and lemon juice to the buttery oils left in the egg pan, heat through and spoon over the top. Serve with watercress and lemon wedges.