Can I season a stainless steel frying pan?
It is not something that I would do - I just use stainless with sufficient oil. But if you really want to try it, then yes, you can make it stick. It is more difficult than with cast iron, but it is not impossible. First, steel does have "pores" (actually crags) on a microscopic level. It is not that much smoother than forged iron, which is also seasoned. Second, we have had enough questions around here of people complaining about "ruining" their stainless when they accidentally polymerized oil onto it. Third, my pans also hold a bit of polymerization on the walls, where splatter meets the hot metal. 

I cannot give you the exact conditions under which it will work, but I don't think there is much difference between the best process for seasoning stainless steel and the best process for seasoning iron. The difference is in that you have a much smaller margin for error. But with good technique and patience, you should be able to do it on purpose.