Ceviche is said to be “cooked” with acid, even if that’s not the most accurate term. And most forms of sushi are made with cooked rice, at miminimum, and not uncommonly with other cooked ingredients. So those things kind of muddy the waters for your point. But a clearer example may be something like beef tartare, a garden salad with a vinegarette, or sashimi. Those things are “prepared”, not cooked, because no cooking is involved in their making. Cooking is specifically the preparation of food utilizing heat. Chefs prepare plenty of dishes that do not involve the act of cooking.