Red onion tarte tatin with rye pastry

I was never a pie/tart maker (one look at the blog index can confirm that), but I do love pies and tarts: I just don’t have much time for them, I guess. Two things that have helped me with this matter is making the pastry in one day and assembling and baking the pie on the other, or keeping an extra batch of pastry in the freezer – nothing like having the pastry ready when you find beautiful