Start by peeling the large yellow onion and slicing it into thick rings, about half an inch in thickness.
In a mixing bowl, combine the all-purpose flour and a pinch of salt. In another bowl, beat the large egg. Set up a third bowl with the Panko breadcrumbs.
Take each onion ring and dip it into the flour mixture, then into the beaten egg, and finally roll it in the Panko breadcrumbs.
In a frying pan, heat the vegetable oil over medium-high heat until it’s about an inch deep.
Once the oil is hot, carefully add a few onion rings to the pan and fry in batches until golden brown, about 2-3 minutes per side.
Using a slotted spoon, remove the fried onion rings and place them on paper towels to drain excess oil.
In a small bowl, stir together the melted butter and hot sauce, then drizzle or toss the fried onion rings in this mixture until evenly coated.
