I have one like that too. I super glued the broken ceramic parts together and it works OK. Remove the resistance unit from the metal frame. Carefully degrease the broken areas making sure you don't damage the resistance wires. Then use a high heat adhesive and glue the broken ceramic back together. Clamp it as the ceramic is porous and it takes a while for the glue ( epoxy or super glue to set ). I used a gel super glue on my broken controller. I don't know how long it will last under heavy use, that's why I suggested a high heat adhesive.
Joe