Begin by opening your tempeh package by cutting the tempeh in half. Place both halves in a pot of water that just covers the tempeh, put a lid on the pot, and bring to a boil. Turn it down to low, and let it simmer 15 minutes.
While your tempeh cooks, you can prepare your peanut sauce. Add all of the ingredients into a bowl and mix until a homogeneous sauce is formed. Prepare your vegetables, or just open up the bag, and chop your peanuts and cilantro. When the tempeh has been cooked, and allowed to cool slightly, slice it into thin pieces.
Remove from the oven, and immediately sprinkle on your remaining ingredients: the broccoli slaw, peanuts, cilantro, and onion.