Peel celery root und cut into cubes of 1cm thickness. Heat milk, cream and butter in a pot, add celery cubes, spice with salt and pepper and simmer all until tender.
For the omelette dough mix well flour and milk. Add eggs and yolk and spice with salt.
Mash celery cubes with a hand-held blender, season to taste and keep warm.
Heat oil in a pan and bake 8 pancakes. Cover with celery puree and wrap them.