I am not sure if I should use formal commands (I suppose not technically imperative, but rather subjunctive since it is formal) or the infinitive from of the verb when writing Spanish recipes. I have seen it done both ways, but I want to know which is *technically* correct. So, if I wanted to say, "cook for ten minutes" would I use "cocinar" or "cocine"? Infinitive or subjunctive?

The impersonal "se" is usually used. "Se cocina....."

Infinitive is technically correct

Well u say things like this: Cocina la sopa por lo menos 30 minutos That sounds Imperative for me.

You can use both, imperative or infinitive, both are technically correct. Cocinar durante 10 minutos Cocine durante 10 minutos (for imperative, you should use the "usted" form)

Maria F is right. Both forms are used and both are correct. If you start using one, do not switch to the other. Corte el tomate en rodajas Cortar el tomate en rodajas Personally, I use the imperative form. Somehow it sounds nicer to me. As you say, always the 'formal' imperative unless you're talking to children. .

technically infinitive cuz para