Heat the milk until it’s hand-hot, meaning it will feel warm. Add the yeast and half of the sugar, then leave for a couple of minutes. Tip the rest of the sugar, flour and salt into a bowl. Pour in the yeast mixture, yogurt, 125ml water and 4 tbsp oil, and mix to a dough (you can use the dough hook on a stand mixer if you like). Knead until the dough is smooth, adding a little water if it feels too stiff, or flour if it’s sticky. It should be pillow-soft when you’ve finished kneading. Leave in an oiled bowl, covered, to rise for about an hour, or until it has doubled in size.