This might be different depending on the speaker, but at least for me Portuguese and Italian are even stricter on interpreting cozinhar/cozer and cucinare/cuocere as involving heat. Like, if I were to say for example ⟨*cozinhei um sanduíche⟩ (literally “I *cooked a sandwich”), I’m almost sure that people would interpret it as “I picked an already prepared sandwich and used it as ingredient for something else”