Heat the oil in a large skillet over medium heat.
Add the onions and mushrooms and sauté for about 1 minute. Add the sausage and brown the sausage on all sides for 2 to 3 minutes. Add the milk, green onions, garlic, salt, and cayenne and bring to a boil. Reduce the heat to medium-low and cook, stirring occasionally, for about 10 minutes. Add the cheese and stir to melt, 1 to 2 minutes.
Add the grits and raise the heat to medium. Cook, stirring, for about 3 minutes, basting the sausage with the creamy mixture. Continue to cook and stir for 7 to 8 minutes, or until the grits are cooked through and tender.
Yield: 2 servings