Heat the oil in a large soup pot over medium heat. Add the onions, season with salt and pepper, and cook, stirring, for 2 minutes. Add the sausage and cook, stirring, for 2 minutes more. Stir in the garlic, thyme, and bay leaves. Add the potatoes and stock. Bring to a boil, then reduce the heat to medium-low and simmer, uncovered, for 30 minutes. Season again if necessary. Add the parsley.
Remove the bay leaves and serve hot.
Yield: 6 to 8 servings