I was thinking how for those cooks who have the recopies that require oats and tomatoes that there is really no value to producing the items. I am a level 50 and lucky enough to find my consummate honey brittle recipe. I have enough gold to buy one or both of the others even but why? Currently there really is no point. I get oats more often than I get tomatoes in the mail and I get about 4 tomatoes a week. I just turn around and sell them no reason for me to keep them I don't have interest in using them there is no benefit to me.
It would seem to me to make some sort of benefit to the community to make the use of the rare items worth it. Currently the structure goes that a green recipe benefits one stat, a blue does 2 but at a reduced rate, and people does all 3 at a even farther reduction. so why not take the most rare item (seems to be tomatoes to me but the developers know the real chances) make that purple recipe return a stat boost grater than the other two purples, take what in my case would be the recipe that uses oats (again the developers would know or could adjust the "drop rate") and have that boost more than the one using pepper (found freely in the world although uncommon) but less than the one using the rarest ingredient.(seems like tomatoes but I state again the developers would be the ones that know for sure or can change the numbers to fit.)
I know there are updates planned to provisioning but I was throwing this out there as something I think could work depending on how things are changed.