Vegetables: onion, leek, carrot, parsley roots, pastinac, celery;
Greens: fennel, parsley, bay leaves, tarragon.
This is “a classic” used most often, though you can use your imagination. Vegetables should be cut in large pieces; this will give the stock deeper aroma. If you want to get a dark stock with a distinguished vegetable taste, before boiling vegetables, prebake them in the oven.