Yes, a PMS-wich.
I use Milton's brand potato bread (haven't found any other to be vegan). Toast the bread, and on one of the pieces, spread the margarine. While the bread is still hot, spread the peanut butter on the slice with the margarine (same side).
The 1/4 block of tofu is cut lengthwise from the block itself - so you're slicing off the top that you see when you open the package. Layer it on the bread* with the peanut butter, slice the avocado and put it on the tofu, and top with the last piece of toast.
*So you might not want raw tofu (but I do!). You can fry it or steam it or whatnot before you put it on the sandwich, if desired.
Your PMS-wich is now ready to eat. You may want to eat it with a tub of chocolate Soy Delicious or a box of Tofutti Cuties. Your choice :)
Sometimes I even like to eat it with ketchup...