Dissolve the yeast in 2 tbsp hot water. Mix flour, sugar, baking powder, baking soda, salt. Add yeast puree and margarine knead well. Form into small buns and place on a tray littered with baking paper (or you can use the tray for muffins). Melt the butter, add the sesame seeds and thyme. Apply each pita top. Bake for 12-15 minutes or until ready in a preheated oven at 200 ° C