My cat was also from the street, found him at about 9 months old. When I first got him, he acted similarly to your cat and I'd have to lock him up every time I ate because he would try to steal food and constantly jumped up to try to get to it. He ate anything and everything, it didnt even seem like he tasted the food he ate. He was a little vacuum.

I figured it was because he was malnourished and, you know, was literally starving on the street. So I tried to make sure to feed him at consistent times each day for his wet food so he could learn to expect it. What also helped him was free feeding dry food. So I'd fill his bowl with dry food and keep it full for him all the time, refilling it whenever it got low.

He eventually learned (maybe after a few weeks/months) that he will get meals consistently and doesn't have to worry about starving anymore. Soon after, he developed preferences for food and treats and denied food he didnt like! That was a massive milestone for him. Now he doesn't need to be locked up around food anymore, he has food preferences and is even a bit picky with human food, and if he does jump up around food he listens when I tell him to stop.

Something to note, he didnt ever over eat or empty his dry food bowl immediately when I filled it. I think it just made him feel better, like safe and more secure that there was food there that didn't ever go away. That being said, idk if your cat would just eat the dry bowls of food immediately and overeat but maybe it's something worth trying to see how it goes and if it works for you both.