2 gherkins, finely chopped
1 shallot, finely chopped
½ tsp Dijon mustard
1 tsp capers, rinsed and drained, finely chopped
½ tsp Worcestershire sauce
few drops Tabasco sauce
salt and freshly ground black pepper
1 free-range egg yolk
100g/3½oz organic beef fillet, finely chopped
1 slice dark rye or pumpernickel bread