Originally posted by TheVaultDweller
Going by their physical condition in Endgame, probably Thor. Looks like he spent a lot of time in the kitchen.
Plus, in 1500 years, I imagine he probably picked up a few things during his adventures.
I have a feeling his diet consisted mostly of pizzas, cheeseburgers and hotdog. Don't ask me why, just a gut feeling.
Anyway to answer the question, we can at least eliminate a few contenders:
Vision is out - we know he sucks at cooking as shown in Civil War.
Steve Rogers is probably out - he's too used to soldier rations plus he boils everything.
Tony Stark is probably out - rich kid like that probably had someone else always cooking meals for him. Same goes for Loki and T'Challa.
The badass bachelor/bachelorette-types are probably not too good at cooking either considering their lifestyle. So that takes out Starlord, Bucky, Gamora, Nebula, Rocket, etc.
So what does that leave us?
Well, it might be one of the family men. Either Antman, Hawkeye or Drax.
It might be one of those used to caring for someone else, like Peter Parker or Mantis.
Personally I think it's Black Widow. Simply because I think culinary arts were probably part of the skillset she was taught to become a convincing undercover spy.