I recently tried the sliders (3 small burgers) at the Keg on Church and front. They are modelled on the Hal burger trio concept and although they are not yet on the menu you can order them if you ask the server.
I have had them twice and have been really impressed. Thick and nicely charred on the outside and juicy and flavourful on the inside. I must admit some trepidation over whether they are 100% ground beef but I still really enjoyed them. Anyone else tried these yet?