It is therefore a question of color, of the appetite that follows, and indirectly of taste: a beautiful food with beautiful colors will please us more than something ugly and shriveled. In the bowl of apples on the table, you will surely and instinctively take the most beautiful available.
All this to say that making beautiful dishes is not only a question of aesthetics, it is also a question of how your guests will have their first impression, and it counts a lot.
In all this quest for beautiful colors, we have two almost antinomic things in the kitchen: green and cooking. Indeed, a lot of green vegetables are very beautiful and green when raw, but if you cook them (too) long, the chlorophyll they contain will degrade and they will become greenish or beige, in short, much less pretty, even if their taste is there.
An emblematic example: leeks, beautiful and green at the beginning, become dull after a long cooking, and a dish that illustrates it well is the leek-potato soup which is in full season as I write these lines.
If you're going to make potato leek soup, you're going to put potatoes and leeks together and cook them, normal, classic. That's a bit of a problem, the potatoes will cook much slower than the leeks, and to get the potatoes to cook properly, the leeks will be overcooked, and a bit dull in color.
Is there anything we can do?
Yes, it's just a matter of cooking time, finely sliced leek is cooked in 4-5 minutes max, potatoes definitely more. So for the ideal soup, cook the potatoes and onion first, and 5 minutes before the end, add the leek and finish cooking until it is tender.
This will give you the ideal leek-potato soup, tasty and with a beautiful, clean green colour, very appetizing.
To sum up: As a rule, green vegetables do not stand long cooking times, so if they have to be cooked with other products, it is always a good idea to cook them last and for as little time as possible.
