Hi W.,
After reading your post, I'm not quite sure whether you intend to (or want to) stay at your job. I am proud to hear that you stuck up for yourself and gave your notice, but then you go on to discuss solutions, and working things out. So I am guessing that you do not want to leave there; you just want them to help you get along better with the chef.
If you 2 have been at odds with each other for 3 years, chances are, you will never feel as welcome there as you'd like.
But if you truly do not want to leave (or can't, for whatever reason), maybe you can consider staggering your schedules, so that you only need to work together for short periods.
In my opinion, it's impossible to separate the pastry from the rest of the kitchen; they need each other.
In terms of him possibly forgetting to tell you about count changes, you can deal directly w/ the manager for that kind of info., no? And if you fear he'll stiff you on ordering certain things, give him your orders in writing, keeping a carbon copy, so you can show him what you ordered, should your items not show.
Honestly, these solutions will not solve the deeper problem, but they may help make your time there easier until you can find something better. Have you looked around for other work? I know you like the pay and the hours, but maybe you can find something even better!!
Anyway, I thought you wanted to move to the Rockies!