Do this
Turn the knife about forty five degrees to the vegetable. Keep the angle the same for every cut. Move the vegetable, not the knife.
Why it works
A slant cut exposes more surface than a straight cut of the same thickness. More surface means more contact with heat and sauce.
When to skip it
Cut straight for anything you want to hold its shape in a long stew. A slant cut has thin edges and they break down first.
