Food substitute - please help

Not sure if this is the right board to post in, so I apologize in advance if it's not supposed to be here. ^^

My cat is on a special diet (Urinary SO) do to repeated urinary blockages. I didn't realize he was low on food, and I don't have any to give him tonight. We have regular cat food, but I'm thinking it's not a good idea to give it to him, because it's what he ate before and he kept having problems. I was wondering if anyone knew of any food items around the house that would be safe to give him in small amounts, just for the night? Meat etc. I can pick more food up tomorrow when the vet opens, but he hasn't eaten since earlier today and I don't want him to go all night without eating. All I know is it should be something with low magnesium. Unless it would be alright to give him a small amount of the Cat Chow? Not really sure what I should do.

If you have any canned food, that would be best. Or some cooked unseasoned chicken or turkey. For one meal it won't make a huge difference but I would make it something wet, not dry food.

Well, you can give raw meat too.... If you have frozen chicken in the freezer, defrost some, and give it to him. Chicken legs, or chicken breast. Turkey is fine too, pork... Beef is a bit iffy as a lot of kitties have issues with it.
Don't give ground meat though......
Cut the meat, put inside of a little ziplock baggie and put inside of a container with warm water for a few minutes and serve.

Oh, thanks guys! I really appreciate the advice. I just wasn't entirely sure what might be okay for him, because he's supposed to be on a special diet. I thought that natural stuff wouldn't hurt, but I wasn't sure if there was something in particular I should give him. For instance I thought of giving him hamburger (because that's what I was making for dinner) and apparently it's not good at all. Haha.

Thank you guys so much. Now he doesn't have to go hungry. <3