With a fork or knife, poke a few holes on the sweet potato. Cover with foil and bake for about 40 minutes. (or microwave for 7-10 minutes with no foil)
In a spice or coffee grinder, add the coffee and spices. Grind until a fine powder. Using a wet cloth, wipe down the mushrooms to clean and get a little moist. Liberally rub the spice mixture on both sides of the mushroom. Add the spice run to the onions. Place on a parchment paper lined baking sheet and bake for 25 minutes.
Slice the tomato and avocado.
When the potato is tender, remove the foil and skin. Chop into ¼ inch round slices. Slice the mushroom on an angle. Assemble the sandwiches and enjoy!
To save on time, you can microwave the sweet potatoes.