What does a fiddlehead fern taste like?

Get em when they’re four to six inches high. Clean out the brown stuff and treat like asparagus. Little salt butter and maybe a touch of vinegar.

or Saute

If they are not cleaned properly and are undercooked they can do nasty things to your belly.

Texture wise, I find them to be very similar to a curled up haricot vert, or a very young, tender green bean.
By the time the brown stuff (that the above poster talks about) is brown, they’re really too developed. You can still eat them, and they are harmless, but it’s best to get them before these fern bits turn. They are still green and tender for about two weeks.
Because of their popularity, people tend to keep them on menus for weeks longer than they should.
Sautee with butter, splash with red wine vinegar and drink rosé with.

Here is a good recipe.

I only had them once. To me they tasted dark green.

They have a crunchy texture, like biting into hard watermelon. They do taste green, as @Sunny2 says. There is also a bit of an earthy odor/flavor.

I haven’t ever had one, but I’ve bookmarked a few recipes in case I ever get the opportunity.

Flatbread with Fiddlehead Ferns

Beer-battered Fiddleheads with Green Aioli