Sulfur + Netherrack = Cinnabar

Cinnabar is a stone material made from Mercury Sulfite, a mixture of sulfur and mercury.

From education edition of the game we know that Netherrack has mercury in it.

A crafting recipe combining sulfur and netherrack therefore should give us cinnabar. 

My specific recipe suggestion would be 1 potent sulfur surrounded by 8 netherrack in a crafting table creates 8 cinnabar.