In a large mixing bowl, combine the sourdough starter, melted butter, milk, sugar, and salt.
Add the flour and mix until a shaggy dough forms.
Turn the dough out onto a floured surface and knead for 5-10 minutes until smooth.
Place the dough in a greased bowl, cover, and let rise until doubled in size, about 4 hours.
Punch down the dough and divide it into small balls.
Arrange the balls in a greased baking dish, cover, and let rise for another 1-2 hours.
Preheat the oven to 375°F (190°C).
Bake the pull-apart bread for 25-30 minutes or until golden brown.
Brush with melted butter and serve warm.
