½ cup all-purpose flour, divided
1 large egg, at room temperature
½ cup buttermilk, at room temperature
¼ tsp. cayenne pepper
½ tsp. salt
¼ tsp. pepper
30 saltine crackers
4 cups kettle-cooked potato chips
2 large yellow onions, sliced into 24 rings (½-inch thick rounds)
6 tbsp. vegetable oil