Preheat grill setting of the oven on medium-high heat. Line a baking tray with non-stick baking paper and cover with a thick layer of rock salt. Arrange the oysters (in their half shell) on the rock salt.
Pour half a tablespoon of Worcestershire sauce over each oyster and top with chopped prosciutto.
Cook the oysters under the grill for 5 minutes or until the prosciutto is crisp on top. Serve immediately – buon appetito.