For the pears: put the water, pear concentrate and lemon juice in a saucepan and bring to the boil, stirring all the time. Add the pears, cover and cook until just soft on a low heat for 5-8 mins. Pour off the water and allow to cool slightly.
For the cheese slices: lay out the slices of bread on baking paper in the baking tin and dribble on some white wine or milk. Place 1 slice of raw ham on each slice of bread.
Mix the cheese, eggs, white wine/milk, spices and garlic in a bowl. Spread the mixture on the slices of bread, and lay half a pear on each slice.
Bake for 10-15 mins. in the upper half of the oven, preheated to 220°C. Remove from the oven, serve on plates and brush or sprinkle a little pear concentrate on the pears.