In Jain Dharma, leek is generally not consumed because it is a root vegetable. Jain dietary principles avoid all underground vegetables such as onion, garlic, potato, carrot, beetroot, radish, and similar items, since they involve more violence to living beings.

So, the simple answer is: No, leek should be avoided in Jain food.

If you want, I can also tell you which vegetables are considered acceptable in Jain diet.