How do I drill a mortise in white oak?

7/8" wide, 2" long, 3" deep through-mortise.

No, I'm not buying a mortiser or drill press mortise attachment.
Yes, I have done this before, but am not satisfied with results.
Yes, I have used a mortise chisel. But my widest one is 3/8".
Yes, I have a big steady drill press.
Yes, I have googled this question and I get movies of "drilling my first mortise".

Questions:
What size drill bit would get best results?
Forstner bit, brad point bit, or spade?
Drill through both sides, with a fence?

In what ways am I ignorant without knowing it?

Thanks in advance.

Brian