I'm originally from Sheboygan, Wisconsin, ground zero for Johnsonville brats, the cube steak steak sandwich, the "hard roll" German-style bun and the butter burger. Not a huge secret to them, although I wouldn't worry too much about seasoning (other than S&P) or forming much of a crust. Slow cook 80/20 and assemble as you described!
~ [I]Scott[/I] ~
[COLOR="Blue"]Blue [/COLOR]Weber Performer + Craycort CI • [COLOR="red"]Brick Red[/COLOR] Weber One-Touch Platinum • Weber 26.75 Kettle • Akorn Kamado • ET 732 • Record-crushing [COLOR="Orange"][B]ORANGE[/B][/COLOR] Thermapen • UDS In Progress