I used 1 large lemon in this recipe, which yielded about 1/4 cup of lemon juice and about 1 tsp of lemon zest. To zest the lemon, I used a Microplane grater. But, you can also use a box grater or knife even. Just make sure to not scrape off any of the white parts of the lemon, which is just under the lemon zest. This tends to be a bit bitter and might add an unwanted bitter undertone to your dish.