Melt the butter in a medium size saucepan; add the flour, mix to make a roux. Continue to cook for a couple of minutes, stirring all the time to avoid burning

Gradually add the beer into the roux, continue to stir to make a thick sauce

Add the grated cheese, mustard and Worcestershire sauce and stir till the cheese has melted and is smooth. Season with pepper to taste

Toast the bread, place on a baking tray lined with baking paper then generously spread with the cheese sauce. Lay the pear slices on top

Sprinkle with a little parmesan cheese and cook under a pre-heated grill till browned and bubbling

To serve, top with chards of grilled prosciutto and a fresh sage leaf