Heat butter in a medium saucepan over medium heat. When melted, add flour and cook, stirring continuously, until roux turns golden brown and begins to smell nutty, about 3 minutes. Add beer, bring to a high simmer, and continue to cook until beer is reduced by half, 4 to 5 minutes. Add shallot and garlic and cook, stirring, until soft, about 2 minutes.
Add cream, thyme, and bay leaf and bring to a simmer, stirring often to prevent boiling over. Continue to simmer until sauce thickens considerably, about 10 minutes. Remove from heat and discard thyme sprig and bay leaf.
Add the cheeses a handful at a time. Season with salt and pepper. Serve immediately with soft pretzels, chips, and jerky.
Yield: about 1 quart