To make the grits, place a 3-quart pot over medium-high heat. Add the chicken stock and bring to a boil. Slowly whisk in the cornmeal. When the grits begin to bubble, turn the heat down to medium low and simmer, stirring frequently with a wooden spoon. Allow to cook for 10 to 15 minutes, until the mixture is smooth and thick. Remove from heat and stir in the cream and butter, season with salt and pepper.
To make the shrimp, place a deep skillet over medium heat and coat with the olive oil. Add the onion and garlic; saute for 2 minutes to soften. Add the sausage and cook, stirring, until there is a fair amount of fat in the pan and the sausage is brown. Sprinkle in the flour and stir with a wooden spoon to create a roux. Slowly pour in the chicken stock and continue to stir to avoid lumps. Toss in the bay leaf. When the liquid comes to a simmer, add the shrimp. Poach the shrimp in the stock for 2 to 3 minutes, until they are firm and pink and the gravy is smooth and thick. Season with salt and pepper; stir in the parsley and green onion. Spoon the grits into a serving bowl. Add the shrimp mixture and mix well. Serve immediately.