In many of these recipes, you very often have two options: zest, or juice, meaning that you use one or the other in the recipe depending on the "tone" you want to give it. Let's say, to simplify things a bit, that when you want the tangy side of the lemon, you use the juice.
And when you want the lemony but more neutral tone, you use
the zest.
Well... in principle it makes sense, but in reality it's not really a good practice, because lemon flavours are both complex and at the same time complementary. In fact, you should not limit yourself to one or the other, but try to combine both, both sweet and savoury.
Let's take a savoury example: lemon chicken. There are 36 ways to make it of course, but do you know the one where you simply pan-fry chicken fillets in a little clarified butter and lemon zest, then drizzle lemon juice over them at the end to finish them off by gently caramelising? The mix of the two, zest and juice, will give a very marked "lemon" tone to your chicken, and a great taste!
And a sweet example: the lemon tart. Here too, there are a large number of recipes, personally I am an absolute fan of the
sanded pastry +
lemon custard, and for the custard, you need to infuse the milk with the zest, and add lemon juice to the custard as soon as it's done cooking. You will also have a very, very marked "lemon" identity, which will have a small effect when tasting.
In summary: In a recipe that uses lemon, always try to use zest and juice.