Heavenly Hash

1.5 # yams (the orange ones in the store, not the yellow ones)
1/2 # crimini mushrooms
8 cloves garlic
1 medium zucchini
2 cups diced yellow onion
1.2 cup olive oil
2 cups mashed potatoes, cooled
Kosher salt and black pepper

Peel and cut yams in to 1"-2" dice.
Toss yams in some of the olive oil, add a pinch of salt and pepper and roast at 350 degrees until soft (about 1/2 hr)
Rough chop garlic cloves.
Cut zucchini in half, then into half moons.
Cut mushrooms into quarters.
Cut onion into 1/2" chunks.
Toss the garlic, squash, mushrooms and onions together with remaining oil.
Roast at 350 degrees until vegetables are soft and caramelized. (approx. 20 mins)
When all ingredients are cool to the touch, get in there with your hands and start to mash it all together.
Add mashed potatoes and mix lightly.
Pinch off a bit, eat it and see if you want to add more salt or pepper. (I smell my food to see if it needs more salt. You'd be surprised how accurate that method is)
Form a patty, using about 1 1/2 cups of the mix.
Heat some more olive oil and a pinch of butter in a nonstick pan over medium high heat.
When the pan is hot, put the patty in the pan.
Let it sizzle in the pan for a bit; peek underneath after about 2 minutes. You're looking for a nice deep browning.
When it is ready, use a spatula to turn the patty over, or just flip it over like a pro! (Make sure no one is watching the first time!!!)
Serve with 2 eggs how you like them (Hash's normally come with poached eggs, but any style is good) and crusty sourdough toast.