Colleen's Notes: Seasoning is key with this dish, season the onions, season the potatoes and season the mushrooms and potatoes. If you like garlic, you could even add in some garlic salt for more of a kick. If you like heat, add in some Cayenne pepper or red pepper flakes.
While caramelizing the onions you may need to add in a little more butter or oil...or even better bacon grease...mmm! Just eyeball them and see if they need any more moisture. To hurry along the caramelization process, you can add in a pinch of sugar if you like.