As everyone else has confirmed, the word here is 'make'. Preparing and putting together ingredients for a cold dish does not count as 'cooking': we make salad. Also note that this holds true even if the salad contains cooked ingredients, such as many Russian salads. First you might cook potatoes, beans, chicken, or whatever else you need, and then, finally, you 'make the salad'. This means that you assemble the components.

Another thing to note: The dictionary definition <em>To prepare (food) for eating by applying heat </em>is actually a little misleading. The key word here is (solid) food, rather than just the idea of heat. Here's why:

We don't use 'cook' for soups, despite the fact that heat is involved. We make soup, even though the ingredients of the soup need to be cooked. For example, you might say "I'm making borscht. It's not ready, though. The beets aren't cooked yet".

We definitely don't 'cook' hot drinks. We make tea and we make coffee, or more rarely, 'brew' these drinks.

Also note that we don't usually 'cook' things that involve dry heat in the oven, especially if they are sweet: in these cases, we use 'bake'. For example, we bake cakes and we bake pies. As with the soup and salad example, the individual components need to be cooked, but we bake the dish itself.

And how about savoury dishes cooked with dry heat in the oven: pizza, for example. Well, in those cases, we generally use the all-purpose verb 'make': we usually make pizza.

Handy tip : if in doubt, use make.

One final point: English speakers never write <em>smth.</em>

99% of English speakers are confused by this strange sequence of four letters and assume it's mistake. Meanwhile, those of us who are used to seeing this Russian habit are curiously irritated by it. Please don't do it! Just write the full word: something.

John has made good point about the word 'prepare' in the context of cooking. 'Preparing' is not the same as 'making' a dish or a meal. In English, the word 'prepare' means to 'make something ready in advance: for something or for someone else'. You prepare food <em>before </em>you cook it.

For example, in many restaurants, a lower-level kitchen employee has the job of preparing vegetables (simply peeling and cutting) so that these are ready for when the chef needs to cook them. Or if you are going to cook dinner at home, you might prepare the ingredients (peeling vegetables, tenderising meat, for example) when you have some spare time earlier in the day. You then set these aside, so that it'll take you less time to make the meal later in the day.

Learners of English tend to mistranslate 'make a dish/meal' etc as 'prepare'. For example, if you say "I'm preparing a salad", this does not mean that you are assembling ingredients for a salad which will be ready in five minutes. It means that you are getting the ingredients ready so that you can make the salad <em>later. </em> For example, you might prepare the salad (wash the lettuce leaves and leave them to dry, boil some eggs and leave them to cool, for example) and then go out to meet your friends. A few hours later, you might come home with your friends, and then quickly make the salad from the components which you have prepared in advance.

I hope that makes sense! As I said earlier - if in doubt, use 'make'.

Make or prepare because you can't or don't put salads into a oven, saucepan, or frying pan etc to cook the salad items.

and to add to La liseuse who got there before I did some research to refresh my memory.

There are some speakers who interchange the words prepare and cook and use prepare in a more archaic form in the verb form to suggest making a delicious meal the difference is vey subtle.

"one whose occupation is the preparing and cooking of food," Old English <em>coc</em>, from Vulgar Latin *<em>cocus</em> "cook," from Latin <em>coquus</em>, from <em>coquere</em> "to cook, prepare food, ripen, digest, turn over in the mind" from PIE root <a href="https://www.etymonline.com/word/*pekw-?ref=etymonline_crossreference" rel="noopener noreferrer" target="_blank" style="color: rgb(131, 0, 29);">*pekw-</a> "to cook, ripen."

late 14c., in the most basic sense, "to make fit for eating by the action of heat," but especially "to prepare in an appetizing way by various combinations of material and flavoring," from <a href="https://www.etymonline.com/word/cook?ref=etymonline_crossreference#etymonline_v_19040" rel="noopener noreferrer" target="_blank" style="color: rgb(131, 0, 29);">cook</a> (n.).

And some speakers will say prepare food or prepare a salad, although this more correctly means to get ready for use at a later time, you prepare the salad by getting the ingredients ready to use or make later.

You could prepare some hard boiled eggs for the salad or prepare a salad to eat later at a picnic by putting in a lunch box. Google searches for preparing salad will give as many results and show the same videos as a search for making a salad