Which part of the mushroom do I use/eat.

Hi,

I’ve done shrooms before but only in like a chocolate bar form. Which part of the actual mushroom should I eat, not sure if the stem or the actual mushroom part is the part with the chemicals. I’m just uninformed.

Also, sort of the same question, if I was going to make some sort of drink or food from it which part would I put inside the blender?