Preheat oven to 400 degrees.
Line a cookie sheet with parchment paper.
Combine flour, chicken stock, oats, cooked lentils, cranberries, celery and egg in a large bowl, Mix well with fingers. If the mixture is too dry, add chicken stock.
On a floured surface use a rolling pin to roll out dough to 1/2" thickness.
Cut out shapes and place on a cookie sheet lined with parchment paper.
Bake for 50 minutes.
Remove from oven to cool. Store in zip-lock bags in a refrigerator.