Research a bit the
harmala subforum for more info
also remember to check things like our
FAQ, as it has info on dosages and a lot of other stuff.
Regarding peganum harmala, you can just eat the powderized seeds, around 3.5g, for MAOI effects, but its very harsh on the stomach. I suggest at least doing a tea with it (powder, boil 3x, filtering each time and adding more water, then filtering liquid and discarding solids, reduce to manageable amount like 50ml per dose, and drink it up). But notice peganum harmala has some other alkaloids apart from harmalas, and these other alkaloids (vasicine, vasicinone, deoxyvasicine) are abortifaciant and uterotonic, so specially for women its counter-indicated (pregnant woman should NEVER take peganum harmala). These alkaloids will come across in a tea too, so you wont be separaitng them
If you want to know the dosage accurately and only have harmalas, then you have to extract them. You can do it, its quite easy and can be done with food-safe ingredients. Check the
harmala extraction guide in the wiki for more info.
I dont think there would be any significant amount of MAOI in chocolate to make a difference, but it certainly wont hurt to eat chocolate with your shrooms. I would be very careful with mixing MAOI+shrooms, a lot of people feel that mixture can get way too intense (including terrence mckenna himself, funny enough). If you take harmalas+shrooms, take very small amount of shrooms first, like half a dried gram or 1g max.