Sift the flour and mix with the baking powder, salt, sugar, flakes and thyme leaves.
Add the softened butter with mustard and sesame seeds.
Make a dough. Wrap in cling film and refrigerate for 30 minutes.
Roll out the rested dough into a thin sheet and cut out different shapes with moulds.
Place the biscuits on a baking tray lined with baking paper. Brush with water, sprinkle with seeds and flakes and place in the oven. Bake at 180 °C for 10-15 minutes.