score:4
There is no minimum UK stay required for you. You are a 'permanent' resident there (for where to make a Schengen visa application purposes) from the day you arrive. It is not even essential to apply from the country of your permanent residency, though one needs a very good reason not to.
Upvote:2
While applying schengen visa you need to submit last three months pay slip and bank statement. So this indirectly states that you should have stayed 3 months inside UK. Hope this helps.