Heat the pear juice, blueberries and sugar in a pot and simmer for 10 minutes, until the blueberries are soft and have given off some colour. Whizz in a blender and keep warm.
For the pancakes, combine the flour, salt, sugar, baking powder and cinnamon in a bowl and work with a fork to remover any lumps. Beat the egg whites with the milk and slowly incorporate the flour mix. Make sure you achieve a smooth batter.
Heat some butter in a frying pan (10 cm diameter) and ladle in some batter - depending on how thick you like your pancakes. (For this recipe and the yield of 10 pancakes, I made them to American-style thickness). Sprinkle some pear over.
Leave to cook over medium heat until little crates appear all over the pancake - a sign that the baking powder is making the batter rise and the bottom should be cooked enough for you to flip the pancake over.
Carefully turn the pancake and cook on the other side until golden brown.