Melt butter in a small saucepan over medium heat. Whisk in flour until a smooth paste forms. Pour in beer, whisking constantly. Add cheese, a little at a time, whisking until a smooth sauce forms.

Remove from heat and stir in mustard and hot sauce.

I used only enough oil to cover the bottom of a small skillet. Heat oil over medium high heat.

Whisk together egg and milk in a small bowl. In another small bowl, whisk together flour, chili powder, salt and pepper.

Working in small batches, dip onion slices into egg mixture, then coat in flour mixture. Shake off excess then place in oil and fry, turning once, until golden brown, about 2 minutes.

Drain on a paper towel and repeat with remaining onion slices.

Place burger patty on pretzel bun. Top with beer cheese and crispy onions. Enjoy!