Finding different ways to use celery leaves besides sticking them in stock is a “chef thing”. Here is a dual recipe. Chopped, it makes a condiment to be used as you might Salsa Verde. Chopped finer in food processor you get a pesto like paste that can be used on pasta, or on slabs of cheese or smeared onto things. For pasta, try it with something like bucatini or try a whole grain noodle with a little more chew and deeper flavor. Barilla makes a “Plus” line that is made with spelt and barley, chickpeas and lentils, as well as semolina, that has a nice flavor that would go well with this recipe. Try it on fish or poultry-it would go well with turkey for instance. Use as a smear for the white meat or use on sandwiches of leftovers later.