Usually, SC is appointed as a reaction to political pressure. This leads to a false impression that appointment of SC is somehow linked to Congress. It's not. The AG can appoint one when the case merits; and the appointment can be done in secret, without even apprising Congress.
Sessions is recused. Rosenstein won’t be doing it as he is part of the FISA conspiracy (he signed one of the related FISA applications).
Nunes and others have already indicated they are prepared for the appointment of an SP. President Trump has given him the green light.
Although he could, Trump will not appoint directly as the optics would be detrimental.
You are referring to the expiration of the independent counsel law that allowed for Congress appointing an SP directly.
Congress can convene and in less than a half day, write a limited reinstatement of the expired law to fund an SP in a budget resolution using a simple majority vote. The President can sign it the same day.
The democrats can howl. No one cares.
I don’t see why Sessions could not unrecuse himself for the sole purpose of appointing an independent SP as there are clear implications of his own deputy involvement and there are substantial crimes to be investigated and pressure to investigate those crimes. After appointing, Sessions can step back into his recusal and his dormancy.