The dish I ate a couple of days ago, and also was very forgetful was braised meat. The dish I ate a couple of days ago, and also was very forgetful was braised meat.

I am not sure what you mean by "was very forgetful". It is typically used to describe a person "She was very forgetful and could never remember to bring her wallet." Saying that the dish was forgetful doesn't make sense here. Do you mean that the dish was "forgettable" meaning that it wasn't anything special? Or "unforgettable" meaning that it was so good that you thought about it for days after?

It was not cooked in a big, decent restaurant, but on a small street by a box lunch store. It was not cooked in a big, decent restaurant, but on a small street by a box lunch store.

I'm not sure if "decent" is the right word to use here. Decent gives the impression that the restaurant is average or above average, implying that the box lunch store might be dirty or below expectations. I might suggest "famous" or "chain restaurant" instead.

I don't know if it's right to say this: it is fragrant and rotten, but some foreigners said that I was using the wrong word "rotten" was wrong, because "rotten" means that some stuff, especially the food, is bad or damaged. I don't know if it's right to say this: it is fragrant and rotten, but some foreigners said that I was using the word "rotten" was wrong, because "rotten" means that some stuff, especially the food, is bad or damaged.

But what I really mean by using 烂 is to describe that the meat is easy to chew or it makes a melting feeling when it comesyou put it into your mouth. But what I really mean by using 烂 is to describe that the meat is easy to chew or it makes a melting feeling when you put it in your mouth.