Think casserole. You can find a lot of recipes that will only use unprocessed food except for things like milk, butter, flour, salt, etc. So, he would get to practice multiple knife skills. Depending on what you think he’s ready for from debone, a chicken or rabbit and then dressing and portioning the meat. If that is too soon, you can buy skinless and boneless meat that he can portion. Then he would get to practice everything from rough chop to fine mince of vegetables and herbs. Possibly even nuts and dried fruits. He gets to saute, simmer, boil, stir, combine, layer, taste, and adjust seasoning. How to make a roux. You can choose a dollar limit and find one that appeals at that price from as cheap as possible to higher ends in the $50 plus range. He could also learn how to use wine or beer in cooking.