If you found salmon bland, then “fishy” tasting fish probably won’t be a problem for you. Cod is a very mild and delicious fish and it’s what I would have recommended.
If fishiness isn’t going to bother you then you can probably cook it any way you want. Oven roasted or pan seared would be good bets. If you wanted something to make it delicious and not mask the taste too much, fried fish in a simple batter can’t be beat imo.
Because humans are social animals, and these sorts of customs are signals to each other that we’re all willing to abide by the social rules our societies follow.