Chop mushrooms by hand until finely diced.
Heat 1 tablespoon oil and sauté mushrooms until all liquid dissolves.
Bring stock to boil.
In another pan, sauté onions and garlic. Cook for 5 minutes until soft, stir in rice and add stock. Reduce heat to low and stir every 5 minutes or until rice is tender. Stir in mushrooms. Let cool on sheet pan.
Remove sweet potato from skin and mash with a fork and 1/2 of the Parmesan cheese.
Add remaining cheese to cold risotto, mix together, add salt and pepper to taste.
Create ping pong-sized balls by using 1/4 cup of rice mixture and a small amount of the sweet potato mixture.
Place risotto balls in flour covering completely. Then dip them into the egg mixture and then into the Panko crumbs.
Heat oil to 350 degrees. Drop risotto balls in frying oil until golden brown.