As it's 'some time later', use 'was'. The restaurant may be under new management or have a new chef so you can't say what the food is like now.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
Anonymouswon't the usage of "was" imply that the food is presently no good?No. It says the food that you ate was good when you ate at that restaurant and says nothing (positive or negative) about how the food is now. Your listener can make up his own mind by going to the same restaurant himself.