Bâtonnet is a French vegetable cut with a precise meaning.
It means a vegetable cut into batons or sticks.
The purpose of this is to allow rapid and easy cooking, or for a vegetable which can be eaten raw (such as a carrot, zucchini or cucumber) to be presented as small, delicate bite-sized pieces as an hors d’oeuvre, etc.
To do this, the first step is to peel and wash the vegetable, then regularize its shape into a rectangle or square by topping and tailing it and squaring off the sides.
Then cut it into 6 cm (2.5 inch) long pieces, then cut each of those pieces into 6mm (1/4th) thick slices. Stack those slices, then cut them lengthwise into 6mm (1/4th) wide sticks.
Vegetable pieces leftover from the cut (i.e. the parts that you topped and tailed and squared away) can be used in soups or stocks, etc. The peelings can be used as stock.