Preheat the oven to 175C. Mix the dry ingredients in a bowl. Bring the water to a boil and add this, the vinegar and egg whites to the bowl, while whisking with a hand mixer for about 30 seconds. Form into 10 pieces and space evenly on a baking try. Bake for 40-50 minutes.
Make the garlic butter while the bread is baking. Mix all the ingredients together and put in the fridge. Take the buns out of the oven when they’re done and leave to let cool. Take the garlic butter out of the fridge. When the buns are cooled, cut them in halves, spread garlic butter on each half. Turn your oven up to 225C and bake the garlic bread for 10-15 minutes, until golden brown.