Mix the yeast into the 1/2 cup of warm water and set aside.
Add the Milk, Butter, Salt, and Sugar to a medium saucepan and heat on top of stove on low heat until butter is melted and sugar and salt are dissolved completely.
Once everything is dissolved, remove it from the heat and let it cool for about ten minutes before proceeding.
Add the saucepan mixture, the water and yeast mixture, and then sourdough starter to a stand mixer and combine.
Add six cups of flour slowly, one cup at a time allowing the flour to get mixed in before adding the next cup.
Dough should be kind of sticky, but not sticking to the side of the bowl too much. If you think your dough is too sticky, add another 1/2 cup of flour.
Add the dough to a large bowl that has been greased. Then flip it over so that both sides of the dough have come in contact with the greased surface of the bowl.
Cover the bowl with a tea towel or saran wrap, and allow the dough to rise for about 45 minutes.
Once the dough has risen, you will punch it back down. You can choose to allow it to rise a second time if you'd like, or you can go ahead and start rolling out your rolls.
Pinch off small pieces of dough and roll them into a ball in your hands. The dough balls should be about the size of a large walnut. Smooth them out pinching the seams together at the bottom of the roll.
Place two walnut sized balls of dough into a greased muffin pan. Fill each muffin tin with two walnut sized balls of dough.
Cover the pans with a tea towel and allow the rolls to rise again. They should double in size.
Then bake each pan for approximately 18 minutes. Once the rolls are baked, rub butter over the tops of each roll while they are still hot.