Combine the wet ingredients together in the bowl of a stand mixer: Sourdough starter, honey, buttermilk, water, and oil.
Once combined, slowly add in flour and mix using your dough hook attachment. Continue to knead with the mixer for 3-5 minutes. To test if enough flour has been added, the dough should tacky but not sticky. If it's too sticky add 1/8 cup flour at a time and continue to mix.
Once kneaded, cover the mixing bowl with plastic wrap and allow to rise at room temperature or in a warm spot. I prefer to proof in my oven leaving the oven light on. This keeps the oven temperature right at 80 degrees and is the perfect spot to proof dough.
Once the dough has doubled in size, it's fully proofed. You can also check the dough using the "poke" test.
Dump the dough out onto a floured surface, then using a rolling pin roll the dough out into a large rectangle roughly 12" x 19".