Pour all the beer into a large heavy-bottomed sauce pan and bring it to a boil; reduce the heat and allow to simmer for a few minutes, until slightly reduced about 7 minutes.
In a medium bowl, toss the cheeses together. Sprinkle the cornstarch over the grated cheeses and toss again to coat.
Add the cheese/cornstarch mixture, a handful at a time, to the bubbling beer, stirring after each addition and allowing each handful to melt completely. Stir in the scallions.
Season with salt and pepper to taste; keep warm over low heat.
Dip your favorite Snyder’s of Hanover pretzels and enjoy (perfect with Snyder’s of Hanover Pretzel Chips)!