I’ve tried throwing some related objects in the pot (flour, sugar, milk) and get nothing. Do I just need to keep trying or do I need to find the recipes?
The cooking system will automatically recognise a complex recipe when the right ingredients are in the cooking pot. Once cooked you can find the recipe in your list of unlocked recipes to reuse. You can try and do it by trial and error, but there are quite a few guides in the guides section of the forum listing the ingredients necessary for all complex recipes. Some of them may be outdated as the devs did change some recipes a few months ago. But most of them should still work.