Please help! joining as a business partner whilst on Tier 2

[Snaj71]

Hi,
I am in Tier 2 General visa and working for an oil and gas. Me and my friends decided to take up a restaurant which is obviously not in my Tier 2 working sector but I just wanted to join them as a partner(But I will not be working for the restaurant). After joining as a partner I will still be working for my sponsor as normal. Am I allowed to join as a partner whilst sponsored by some one else on Tier 2 General and what I have to do for doing so?
I have checked few posts but none of them make a clear sense to me. So It would be a great help if someone could explain this in detail and guide me.

Many Thanks in advance
Snaj