First, make your Tangzhong. Heat a pan on medium-high and add the flour and milk. Wisk until the mixture thickens and forms a consistent paste. Set aside to cool.
Add the remaining flour, salt and sugar to a bowl. In a jug, mix the remaining milk and yeast. For this recipe, I used fresh yeast but you can also use dried yeast, just allow it to sit in the warm milk for 5 minutes.
Pour the liquid into the bowl of flour and add the Tangzhong and vegan butter. Incorporate all ingredients and hand knead for around 10-15 minutes. Once you have a nice shiny ball of dough, leave it to rise in a greased bowl for 1 hour.
Once the dough has doubled in size, place it onto your work surface and push out the air. Check the weight and divide into 6-8 balls (6 for larger buns, 8 for small to medium-sized). Place them on a tray with some parchment paper, cover and leave them to rise for another hour.
Preheat your oven to 180° C / 340° F. Apply your vegan "egg" wash to the buns and add sesame seeds, poppy seeds or any other kind of seeds if you wish. Place the buns inside the over and bake for 10-15 minutes. Keep a close eye on them and remove if they are browning too much.
Serve with your favourite burger and topping.