Preheat the oven to 200 ° C or convection 175 ° C.
Thaw the puff pastry a little and fold in the pastry squares about 1/2 cm on each side and press down. Place on a baking sheet lined with baking paper, whisk the egg yolks and brush the dough squares with them. Bake in the oven for about 8 minutes.
In the meantime, cut the washed spring onions into rings and mix with the créme fraíche, add dried or fresh (leaves plucked) thyme, salt and pepper.
Fill the pre-baked tartlets with the mixture, place the goat cheese thaler on top and bake in the oven for another 10 minutes.