Lemons  are good for curd to put in lemon tarts and bars. it's a slightly complicated cooking process since making the lemon curd requires you to use a double boiler to gently cook the egg yolks. Oh, but what a tasty  treat! The sweet and sour flavor is worth every minute.       Grating lemon zest into muffins and cookies is a fine way to liven them up. if you have some other citrus in your refrigerator, don't fret your pretty little lemonhead-- oranges and limes have a positive influence on pastries too and behave the same way as lemons in baking.