Slice Onion into thick rings.
In a small bowl combine sourdough starter, buttermilk, salt, and garlic powder. Set aside
In a separate bowl add bread crumbs.
Heat 1/2 inch of oil in a cast iron skillet or dutch oven. Once hot, frying can begin!
Add a few onion rings to the batter, transfer one at a time to breadcrumb. Shake of excess and add in a single layer to hot oil.
Fry rings for 2 to 3 minutes per side until golden brown.
Transfer to paper towel lined pan and keep warm. Serve hot along side honey mustard for a delicious side dish!