Round, brown, hard-shelled seed, A squirrel's autumn treasure, Sweet treat in the shell.

I sit on a knight, but I’m not a hat, I flutter and shine what do you think of that? I’m the top of a wave when it’s tall and white, I curl and I crash with a foamy bite.

Fans spin up, and multicolored lights glow, A machine useful for many things, but the lights are just for show, There might be water inside, there's almost definitely a sink A complex conglomeration, we taught to think

In my grasp, the nectar flows, A chalice where the vintage goes. With stems so fine, I raise a toast, To kings and queens who love me most.

You can find me in burgers. You can find me in tacos. I'm not a vegetable. But, I'm also not a fruit. I'd ask you to get into the meat of this riddle. But that's not relevant either, is it?