Sorry, we cannot "define a conscious being as one that is aware (if not perceptive) of both itself and it's surroundings."

You've got to distinguish (if not define) consciousness, awareness and perception. The latter two are usually understood in terms of information content and flow. Keep digging and you get to symmetries and randomness. Think through carefully enough and you'll take questions like 'is water in a bowl aware of the bowl, since it conforms to its shape?' seriously.

If you simply want a literal answer that takes your categories in reasonable everyday senses, you could get the behavior you want with a stabilizing feedback loop containing a single integrator (which can technically be said to model it's environment and itself in a simple way). That's way simpler than even a single cell.

I think what you are really asking about is "recognizably human like cognition" which is a question about the smallest Universal Turing Machine in the only meaningful interpretation I can imagine. That takes a few hundred bits to describe and I expect could be realized via a few hundred neurons.

None of this has anything to do with consciousness in the sense it is discussed in the philosophy of mind.