I have made up the two versions of the same example below, using a different adverb each.

(1) We had a fantastic dinner at ABC Restaurant. The food was absolutely delicious. We all enjoyed it gleefully.

(2) We had a fantastic dinner at ABC Restaurant. The food was absolutely delicious. We all enjoyed it mirthfully.

Which adverb works better in this context. Thank you very much for all your help. I really appreciate it.

In my opinion, neither adverb goes well with 'enjoy'.

More appropriately, enjoyed it immensely, enjoyed it thoroughly, or maybe enjoyed it greatly.

Neither the Google Ngrams Viewer nor the fraze.it corpus shows any instances of enjoyed it gleefully or enjoyed it mirthfully. (I don't find that surprising because these are very unusual combinations of words.)

CJ