1) Griddle the sliced garlicwurst in a panini press. Split knish in half and scoop out half of the potato mixture from inside. Spread mustard on both open faces of the knish.
2) Place two slices of cheese on each open face of the knish. Place grilled slices of garlicwurst on the sandwich, followed by four slices of thick pickle. Close the sandwich and cook in the panini press.
Garnish with the remaining pickle slices and serve.