Concave pocket?

Yes, this can be done, but it requires a bit of math/checking to get the thickness.

Basically, it looks to be the same as a spoon/scoop, for which see:

So one draws the geometry:

Note that the surrounding geometry must be closed so that it may be removed from and modeled in 3D:

Apply | Show 3D

Then select the circle and make appropriate settings:

Apply | Show 3D

To check the depth draw a small piece of geometry:

Then model it to be equal in height to the dimension which you wish to check:

Apply | Show 3D

(then delete/disable the object after)