here are all the recipe locations i have found
where to look in Chris,Wally, Hughs house:
look at around the refrigerate and the sink you should find a recipe
where to look at Rock,Tim,Rubys house:
look at the trees in the office to find a recipe. Go into the kitchen ad look at the wall right against where the door is. I think this is more of a tip than a recipe but go up stairs and look at the statues.
Where to look at the seed farm: look inside the house and look beside the bed.
in Galens house: look at Nina's picture.
In Kates room: you will have to look around but im not sure just look at the tables.
Just keep talking to takakura and he will give you a few recipes and look around his room
Last is the villa: look at all the pictures one of them have a recipe behind it.
also there are more but i cant remember them ill post more if i remember.
Just keep looking around houses you may find more than recipes ;)