Buy ZWILLING Sharpening stone

The stone has a nice weight to it and doesn't slide around on the counter while I'm working. Twenty passes on each side brought my paring knife back to slicing tomatoes without squishing them.

My chef's knife finally glides through tomatoes again after about ten minutes on this stone. It builds a nice slurry quickly and the edge it leaves is genuinely razor-sharp.

I was skeptical about sharpening my own knives, but after ten minutes on this stone my chef's knife went from dragging through tomatoes to slicing them cleanly. The surface has enough grit to actually remove metal without gouging the edge. My knives cut like new again.