Japanese grilled eel is pretty tasty, it's nothing like the eels in jelly. So if it is eel chances are it's not going to taste bad.
That's a reference to Touhou's Mystia Lorelei. She runs a stand of exactly this description, though IIRC she serves lamprey, not eel per say, as a "cure" for night blindness... which her singing causes.
Judging by the context, should the words read something along the lines of gaining extra weight rather than Extravagant Meat?
何!?Wh... what do you mean!?All that remains is guilt and regret... and extravagant meat.The only thing that can be gained at their destination is temporary gratification...Feels like the song's leading them somewhere...What a mysterious ditty...Sure is late, though.You mustn't go, Hornet.Wait! Where are...I'm back!Hmm... Could go for a little something to eat...Sara!!MENACINGNoodle shop
HOUSHOU