Crumble the sausage into a large saute pan over medium heat. Brown, and drain. With a slotted spoon, place in bowl and set aside.
Poor the oil into the same pan, add the onion and saute til tender. Add the garlic, mushrooms, turmeric, salt, pepper, and oregano and cook until the mushrooms are limp. With slotted spoon, place in the same bowl as the sausage.
Add rice to the same pan. Toast for about a minute or two, stirring frequently. Add 2/3 c of the stock. (be careful, it will steam.) Stir well, scraping the brown bits off the bottom of the pan. Bring to low simmer. When the stock is nearly absorbed, add another 1/3 c. Continue doing this, 1/2 c. of stock at a time, until the stock is gone and the rice is tender. This takes about 20-30 minutes.
Stir in the sausage mixture and cheese, until it is well combined and the cheese is melted. Stir in the parsley and mix well. Serve immediately.