First make your bread. Place the flour in a large bowl. Add the salt and caster sugar to one side of the bowl, and the instant yeast to the other side (yeast and salt don't like to be in direct contact). Add in the butter and about three quarters of the milk. Mix the dough together with one hand. Add in more milk, a bit at a time until you've picked up all the flour from the sides of the bowl and you have a soft (but not really sticky) dough. You may not need all the milk.
Lightly oil your work surface with a litte olive oil, then turn your dough out onto the surface and knead for 5-10 minutes. It will be a bit sticky at first, but will eventually get smoother. Clean and dry your bowl, wipe it with a little olive oil and place your dough in the bowl. Cover with clingfilm and then place in a warm room for 1 hour to prove.
Take a large frying pan - approx. 30-35cm diameter. Place an oven proof upturned bowl (approx. 16-20cm diameter) in the middle of the pan. Then lightly brush the outside of the bowl with a little olive oil or cooking spray. Put to one side.
Once the dough has proved, turn it out onto a lightly floured surface and knock the air back out of it by folding it in on itself repeatedly. Then you need to divide up your dough. You can do this by eye if you want a more rustic version. If you want to be precise though, weigh your dough and divide by 30. You should get 30 portions weighing about 30g each. Roll each portion into a ball. Make sure the top is smooth for each. I usually roll each ball and then tuck any messy bits underneath. Arrange the dough balls around the small bowl. You can see here, I did 11 balls on the inner circle and 19 on the outer circle. Cover in clingfilm and leave to prove for another 30-40 mins.
Whilst the dough is proving, preheat your oven to 190c and also make your dip. Reserve the chives and 20 grams of the cheddar, then mix all of the other dip ingredients together until combined.
Once your dough has proved, carefully remove the bowl from the centre of your dough ball pan, and pour the dip into the centre. Sprinkle with the reserved cheese. You can also sprinkle the tops of the dough balls with a little bit of plain flour if you like. Place in the oven for 20-30 minutes until the buns and dip are golden. Take out of the oven and leave to cool for 10 minutes. Then sprinkle the reserved chives and a bit of black pepper on top and serve!