How to remove dual fuel cooker with hard wired oven and gas hob

[acomiskey]

Hi All,
Fairly new (or at least to posting) on this forum so apologies if this is on the wrong area etc.

I've started work on instilling a new kitchen and want to remove a dual fuel cooker which has hardwired electric oven and a gas hob. When I pulled the cooker out I was expecting to see some sort of tap/valve to stop the gas supply that would then allow me to disconnect the hose supplying the gas. However, not having dealt with this sort of thing before I was surprised to see no handle etc.

Tried to attach an image of what's behind the cooker where the gas supply comes in but I don't seem to be able to for some reason - the supply pipe seems to run to some sort of brass fitting and then onto the hose but I can't see how to stop the supply - any advice on how to safely disconnect the cooker would be appreciated.

Thanks in advance.

Adam