In a robot, work the flour with salt and butter, add the egg yolk and stir until you get a homogeneous dough. Add the poppy seeds and knead quickly, avoiding crushing them. Wrap in plastic film and cool in Freddy for 20 minutes. Put a low pan on the bottom.
Boil two liters of water with vegetables and bay leaf. When it boils put the chicken thighs and cook for 25 minutes. Check that the meat attached to the bone is well cooked. Put the meat with its broth in Freddy in the low pan and cool for an hour.
Remove the dough from the Freddy, roll out half a centimeter thick and coated with moulds from the tartlet. Bake in the oven at 200ºC for 10 minutes. Remove from the oven. Cool for 15 minutes.
FINISHING AND PRESENTATION
In the meantime, cut the celery into tiny cubes. Mix it with the yogurt and mayonnaise. Remove the tartlets from the Freddy and stuff them. Decorate them with a slice of radish and a few leaves of marjoram.