In a medium sauce pan over medium heat melt the better. Whisk in the flour.
Take the pan off of the heat and whisk in 2 tablespoons of the milk until smooth. Then whisk in 2 more tablespoons. Add 1/4 cup of the milk and whisk that until smooth followed by the final 1/4 cup of milk.
Stir in 1/2 cup of the beer, dijon, garlic powder, salt and cayenne. Return the pan to medium heat and stir until thick and bubbling, about 2-3 minutes. Remove from heat.
Add the cheese one big handful at a time, whisking after each addition to melt it in. Taste and add more garlic, salt and cayenne if desired. I also add more beer if needed to thin it our a bit. You can also do this later if it becomes to think as it cools. Garnish with a pinch more of cayenne on the top to add a little more spice.
Cut a hole out of the top of each of your pretzel rolls. Pull some of the bread out to give you a nice amount of space for filling them up with the hot beer cheese dip.
Serve the pretzel bowls filled with beer cheese dip on a platter and sprinkle the extra bread around the bowl for dipping.