(我沒辦法輸入簡體字，如果真讀不來，麻煩你再自行繁轉簡一下。） 前三句很好，很自然，但後三句要改一下。改法是把「今晚的」縮短成「今晚」，然後再把它移到「你」的前面或後面都可以。 ( I can't type simplified Chinese and if you do have trouble reading the text, please do some trad/sim convertion.) The first three are good and natural, but the other three could use some tweak. All you need to do is shorten 今晚的 to 今晚 and then move it to the front or back of 你.

What are you going to cook tonight? （你）今天晚上煮/吃什么？（吃 is more common than 煮 in oral language） What have you cooked for dinner? (你)晚餐做了什么？ / （你）什么了？ 1.If you use these two sentences in real life, we all know what is the time and who you are talk to, so it is not very need to point out "you" or "dinner". 2.The first sentence is "going to", so you do not know what kind of dinner exactly.We use this question when you see your friend or your wife planning to supermarket or coming back from shopping. I mean, in the duration of preparing and you have no idea about the dinner. 3. The second sentence is "have cooked". So the action is finished. But you have not saw the dish and you want to know. Maybe you just come back home. 4.今晚的晚餐你煮了什么？ If you really want to use complete sentence, I suggest you put object in front of the sentence. It emphasizes the thing you want to know and the answer would follow the same order easy to understand.

what are you going to cook for dinner? 晚餐你要做什么（吃的） what have you cooked for dinner? 晚餐你做了什么（吃的） 以上两句只是时态的差异。