'He cooks food in the evening' is not correct...weirdly enough
"In the evening" is "om aftenen" in Danish. "Han laver mad i aften" is strictly a statement about this particular day whereas "han laver mad om aftenen" talks about no specific day.
In the evening could be any eveving. This sentence means tonight specifically.
It means "tonight." Also it's an incorrect translation, as danes use present tense for things that will happen very soon. You might have also noticed that they say, "he speaks with me tomorrow"
Why can't it be 'he cooks dinner tonight'? It sounds more natural than just generically 'food'.
It can be "he cooks tonight". "food" is implied in English.
Because dinner is aftensmad. Food is just mad!
"Laver mad" is just how you say "cook" in Danish.
Can i say "THIS evening"?
Yes, "this evening" is accepted (provided the rest of the sentence is correct)
Aften is evening. Nat is night