Follow the hoses from your valve covers. One goes into your throttle body, another goes into the intake pipe. Any oil vapor gets sucked either into the manifold directly (no boost) or into the intake pipe (turbo producing boost).
It's not uncommon for a lot of oil to get through the system this way. Since your turbocharger seems tight, and the seals in a turbo are the non-contact type, do a compression or a leak down test.