To julienne vegetable is to cut them into very slender little sticks, like very thin matchsticks. This term is usually used with firmer vegetables, such as carrots, beets, or zucchini. To chiffonade is to cut very thin slivers or strips of a leafy vegetable. Occasionally you might see a recipe call for julienned basil, and basically, what the recipe writer is looking for is chiffonaded basil.