What is the classifier for a piece of ginger? [closed]

My French friend told me that he had to chop up 20 gingers at work. He works in a restaurant.

I told him it sounded funny and a classifier is required.

It got me thinking, what is the classifier or counting word for ginger?

I’m referring to the funny shaped lump of knotty root, not the ground up or chopped up form.

For example 20 heads of cabbage, 20 sticks of celery etc.

I suppose you could say 20 ginger roots, but what about 20 roots of ginger?

Is there another term I’m overlooking?

Solution 1:

If each piece of ginger is a bulbous protrusion from the root, you could call it a knob of ginger.

In the sentence it would be: "My French friend told me that he had to chop up 20 knobs of ginger at work."