To be honest it's not very difficult to get started and if you want to, there's no reason why you can't just jump in and try it yourself.
Ingredients typically have adjectives which could give you an idea of their effect. The hearty radish for instance boosts your health when cooked. Spices typically augment the effects of the main ingredient. Using hylian herbs for instant make a hearty radish dish restore more, all or even extra hearts. When it comes to elixirs, I didn't make many casually, but I assume you can extrapolate the same way. You need your main ingredient for the boost it gives you and then the monster part for the elixir.
Nintendo wants you to extrapolate from incomplete data so making food is fun. However, if you want to speedrun you should use a guide. If you don't want to speedrun, why are you one speedrun.com.
I believe the monster part doesn't matter and that it's more about how many of the main ingredient you use. I don't think there's any reason to ever use more than one monster part. But the best way to find that out is to experiment if you don't want to use a guide.
haha it's alright, it's just not often you get people asking general questions about a game on speedrun.com. It's fine actually I just didn't expect to see this type of thing in here haha
tbh, u don't really need food to speedrun this game. u can use food to beat the bosses in a faster time, but u don't need food or elixirs. What I would do is look it up on the Internet, or just watch other runners cook and take notes of the ingredients they used. It is simple really. You can try going to IGN. I think they have a list of everything Breath of the Wild (shrines, side quests, food, etc.).
i made an any% guide, its a bit rough and it will probably be better if you just watch a few runs and chat with people on the discord and twitch. https://imgur.com/a/bWcgo . if you all want i can probably do one for ad and all shrines too