In measuring jug, combine the warm water, milk, yeast and sugar.
Give it a good whisk and let it rest until the yeast activates and a bubbly foam appears on top (roughly 5 minutes).
In a large bowl, add the flour, salt and butter.
Rub the butter into the flour (as if making pastry) until breadcrumbs have formed.
Stir in the yeast mixture and one of the beaten eggs.
Bring the dough together into a ball then knead on a lightly floured surface for 10 minutes.
Place back into the bowl and leave it to rest in a warm place with cling film over the top of the bowl for roughly 2 hours or until it has doubled in size.
In the meantime, line a baking sheet with grease proof paper.
When the dough has doubled in size place the dough on to a lightly floured surface and knock the air out of it.
Divide the dough into 8 equal pieces and shape them into balls, rolling until they are smooth.
Place on to the baking sheet leaving a gap (roughly 5cm apart).
Cover loosely with cling film and leave in a warm place again to rise for roughly 1.5 hours.
When the buns have risen again, beat the remaining egg and gently brush each roll with the egg wash.
Sprinkle over sesame seeds.
Preheat your oven to gas mark 6 or 200C.
Immediately before baking, place an oven dish in the bottom of the oven with an inch of water in the bottom (this will create steam as the buns bake).
Place the buns in the centre of the oven and bake for about 15-20 minutes or until golden brown. Turn the buns out on to a wire rack to cool before eating.