So the first session my buddy wanted to cook a 2ft tall mushroom, for a mimic, to convince it to leave a gnome settlement. Thinking fast I told him to make a survival check to properly cook it.  Was this the right thing to do?

There isn't really any right or wrong way of doing it - that said there is a Cook's Utensils tool set. If they have proficiency with the tool then they can add that - if they don't have the tools then they'd have to improvise something. Etc.....

I make cooking WIS checks.

Player's Handbook Page 154 talks about this.

Basically, Cooking is an Artisan Tool Proficiency, just like Smith, Herbalist, or Mason.

Quote from Mog_Dracov >>

Player's Handbook Page 154 talks about this.

Basically, Cooking is an Artisan Tool Proficiency, just like Smith, Herbalist, or Mason.

 Yeah, but those rules are deliberately nonspecific. Tool checks are ability checks, but the ability used depends on the task.

True,  but I am pointing out that Survivial skill should not be relevant.

Like you, I think the stat it should be based on is Wisdom. 

Basic foraging and hunting is wisdom.

But if you already have the ingredients and want to make a meal, this is using logic and active thought to follow a recipie, blend ingredients correctly, cook the right temperatures and methods and use the right utensils. So, intelligence is most fitting. At least based on the details found in "Using Each Ability" section of the PHB about what each ability is intended for.

The tools themselves are left without a specific ability associated by design, since the tool can be used in more than one way for more than one task. This is something I applaud in the design, not grumble about.

The only proficiency that should be relevant is the Cook’s Utensils.

As to what ability to roll, I usually vary it depending on method/presentation. A scientific/gastronomic approach would be Intelligence. If you’re trying to boldly express some idea through the flavor profile, I’d call for Charisma. “I just taste it every few minutes to see if it’s good and keep going with that because I can’t think of anything else” would be Wisdom.

Quote from SagaTympana >>

The only proficiency that should be relevant is the Cook’s Utensils.

As to what ability to roll, I usually vary it depending on method/presentation. A scientific/gastronomic approach would be Intelligence. If you’re trying to boldly express some idea through the flavor profile, I’d call for Charisma. “I just taste it every few minutes to see if it’s good and keep going with that because I can’t think of anything else” would be Wisdom.

 Maybe Dex for something finicky like a soufflé or a Genoese sponge cake.

No wrong answer.

Survival would have been what I would have chosen. Wisdom for sure.

Also make flour, sugar, and salt readily available. Players can be so creative with these basic ingredients. 

Quote from Fattsgalore >>

No wrong answer.

Survival would have been what I would have chosen. Wisdom for sure.

Also make flour, sugar, and salt readily available. Players can be so creative with these basic ingredients. 

 
Unless the developers come in and say "Cooking is always rolled with Wisdom!" - you have no basis and certainly no authority to make the statement of what is or is not a "wrong" answer.

It is, by design, up to individual DM interpretation based on the scenario.

It's one thing to say what it should be in your opinion, but it is not OK, at all, to say other people's opinions are incorrect.

Quote from Cyb3rM1nd >>

Quote from Fattsgalore >>

No wrong answer.

Survival would have been what I would have chosen. Wisdom for sure.

Also make flour, sugar, and salt readily available. Players can be so creative with these basic ingredients. 

 
Unless the developers come in and say "Cooking is always rolled with Wisdom!" - you have no basis and certainly no authority to make the statement of what is or is not a "wrong" answer.

It is, by design, up to individual DM interpretation based on the scenario.

It's one thing to say what it should be in your opinion, but it is not OK, at all, to say other people's opinions are incorrect.

 I think what they meant was “[There is] no wrong answer....” as opposed to “No, wrong answer.” 

That missing comma made the difference in my interpretation.”

Quote from IamSposta >>

Quote from Cyb3rM1nd >>

Quote from Fattsgalore >>

No wrong answer.

Survival would have been what I would have chosen. Wisdom for sure.

Also make flour, sugar, and salt readily available. Players can be so creative with these basic ingredients. 

 
Unless the developers come in and say "Cooking is always rolled with Wisdom!" - you have no basis and certainly no authority to make the statement of what is or is not a "wrong" answer.

It is, by design, up to individual DM interpretation based on the scenario.

It's one thing to say what it should be in your opinion, but it is not OK, at all, to say other people's opinions are incorrect.

 I think what they meant was “[There is] no wrong answer....”

 
That would make more sense.

I apologise if I jumped to the wrong conclusion.

Quote from Cyb3rM1nd >>

Quote from IamSposta >>

Quote from Cyb3rM1nd >>

Quote from Fattsgalore >>

No wrong answer.

Survival would have been what I would have chosen. Wisdom for sure.

Also make flour, sugar, and salt readily available. Players can be so creative with these basic ingredients. 

 
Unless the developers come in and say "Cooking is always rolled with Wisdom!" - you have no basis and certainly no authority to make the statement of what is or is not a "wrong" answer.

It is, by design, up to individual DM interpretation based on the scenario.

It's one thing to say what it should be in your opinion, but it is not OK, at all, to say other people's opinions are incorrect.

 I think what they meant was “[There is] no wrong answer....”

 
That would make more sense.

I apologise if I jumped to the wrong conclusion.

 Everyone has been extra touchy lately. It’s almost as if the entire world is feeling cooped up and angry in general lately....

I think I accidented a flame war...

Quote from PatrickDees >>

I think I accidented a flame war...

 Nah. It’s all good, just a slight misunderstanding over punctuation is all.

My DM has always used Survival for cooking if we want to prepare anythign other than the most basic of meals (which require no roll). I've just kept that as well since it seems to maek sense to me.

Quote from TransmorpherDDS >>

My DM has always used Survival for cooking if we want to prepare anythign other than the most basic of meals (which require no roll). I've just kept that as well since it seems to maek sense to me.

 Well than what do you use Cook's Utensils proficiency for?

to be honest i have it so if they have cooking utensils then they can cook most things (not a 2 foot mushroom)

To be honest, a two foot tall mushroom would probably be so woody and fibrous as to be inedible. (Former amateur mycologist.)