Start by slicing the onion into thick rings. Aim for about half an inch in thickness for that perfect bite. Separate the rings and set them aside.

In a large mixing bowl, combine the Dijon mustard, beaten egg, melted butter, and hot sauce. Whisk them together until smooth. This mixture gives the onion rings their signature flavor.

In another bowl, mix the flour, garlic powder, and Panko breadcrumbs. The flour sets up a gripping layer, while Panko ensures that delightful crunch.

Take an onion ring and dip it into the wet mixture, allowing any excess to drip off. Then, coat the ring in the breadcrumb mixture. Repeat this process for all the rings.

Heat the vegetable oil in a deep pan over medium heat. Once hot, carefully add the coated onion rings, frying them in batches. Do not overcrowd! Each ring should have space to float and get that golden color.

Once the onion rings turn golden brown (about 3-4 minutes), remove them and place them on a plate lined with paper towels. This helps absorb excess oil. Serve hot with your favorite sauces.