If you prepare them, whatever the recipe, you will sooner or later be confronted with the problem of cooking.
And that's normal, that's the difficulty of preparation, and there are two main ways:
1) The "we hardly cook", to keep the pearly scallop inside, they are also often followers of the scallop carpaccio, the scallop cut into thin strips and served raw, with a dash of lemon and/or oil.
It is cooked on a hot surface without excess, or even in the oven, to preserve the pearly side already mentioned.
Of course they think that going further in cooking is a heresy, this school is very present in the chic restaurants.
At Robuchon's, in one of his books, the scallops are only cooked for 2 minutes in the oven.
Well, I don't hide from you that I have trouble with these short cooking times, but it is a school that respects itself.
2) the "on saisit très chaud" (very hot), are adapted from a hot cooking surface (frying pan, plancha, griddle), on which the nuts are seared (butter or oil) for 2 or 3 minutes on each side to obtain a nice colour.
The "burning" side plus "each side" gives very colorful and tasty nuts, but let's not forget the butter. By the way, the plancha is ideal for this cooking.
It should be done quickly if possible, otherwise an overcooked scallop becomes hard as a tennis ball.
Of course these are not the only cooking methods, you can consider many others such as in papillotes or poached for example, you just have to keep in mind that the scallops must be cooked, but not too much ...
Then, and whatever the chosen method, you have to think about 3 things:
1) Rinse the nuts well
2) Remove the "foot" (small hard part on the side of the scallop)
3) Dry the nuts (paper towel or cloth), top and bottom, before cooking them.
This is not always easy, but remember that you need "dry" nuts to start cooking, it always works better.
You may also wonder if you should keep the "coral", the orange part of the shell that is attached to the scallop?
It's just a question of taste, personally I find it a bit dull and not very interesting, I don't keep them, but that's debatable.
In some old recipes, a bit dated, the coral is used separately to constitute a sauce base, a bit like a thickener, but it's the same observation, not much gustatory interest, rather aesthetic.
To sum up: cooking scallops is always a delicate matter, you have to be precise and relatively quick.