For the grits: Bring the chicken stock, the cream and butter to a simmer in a heavy saucepan. Gradually whisk in the grits. Reduce the heat and simmer until the grits have thickened, 15 to 20 minutes, stirring occasionally to avoid lumps. Once the grits are thick and creamy, stir in the cheeses and adjust the consistency with stock and/or cream and season with salt and pepper. These grits provide a wonderful bed to soak up the flavor from the sausage, shrimp and veggies.
For the sausage, shrimp and peppers: Heat the olive oil in a large skillet. Add the sausages and brown. Then transfer to a plate with a slotted spoon, leaving all of the fat in the skillet. Add the garlic, bell peppers and onions to the skillet, sprinkle with salt and pepper and saute until tender, 5 to 7 minutes. Add the shrimp and saute until they begin to turn pink, 1 to 2 minutes. Add the reserved sausage and the chicken stock to the skillet and let reduce a bit to intensify those flavors. Stir in the butter at the end and garnish with parsley.
Serve the sausage mix over the grits.