Beat the flours, eggs, milk, water and a pinch of salt together to make a smooth batter. Leave this to rest for 30 minutes. Melt half the butter and leave to cool. Thinly slice the Gruyère AOP.
Combine the melted butter with the batter. Cut the slices of bacon in half and dry fry them. Remove from the heat and pat dry with a paper towel. Wipe the frying pan clean and melt some of the remaining butter. Add ⅛ of the batter and swirl it around the base of the pan.
Cook each pancake for 2-3 minutes on a medium heat until golden, and then flip. Put a few slices of bacon and Gruyère AOP on top and cover the frying pan for about 3 minutes to melt the cheese. Fold approximately an inch (3cm) of the edge of the pancake over the filling and keep them warm, if necessary, in a preheated oven at 125°F (50°C). Rinse, dry and chop the parsley and use this to garnish the pancakes.