Form the burger patties by combining the ground angus, salt and pepper, Worcestershire sauce, and favorite burger seasonings in a bowl. Divide and press into 4 large patties. Cover and refrigerate until ready to cook.
Preheat your grill and clean the cooking grates.
Meanwhile, combine the mustard, flour and cayenne in a small pot over the side burner of the grill or on the stove over medium heat. Melt in the butter and cook for 1 minute. Slowly whisk in the beer a little at a time to prevent clumps and make your roux. Add in the Worcestershire sauce and add the shredded cheese a little at a time. Stir until melted and smooth. Remove from heat and stir in the egg yolks until smooth.
Set out a small iron skillet on the grill. Create the burger by stacking the buttom bun, covering in lettuce, and then the burger patty. Slather a scoop of the rarebit sauce over the burger and cover the lid to toast for a minute or two. The cheese will thicken and run a bit. Carefully remove from heat, add bacon, tomato, pickles and the top bun.
Serve while hot.