In a soup pot, heat the EVOO over medium. Add the sausage and cook until browned and crumbly, 5 minutes. Transfer to a plate. Add the potatoes to the pot, season with salt and pepper and cook until lightly browned, 5 minutes. Add the fennel, onion, garlic, zucchini and tomatoes. Cover and cook until the vegetables soften and the tomatoes burst, 7 to 8 minutes. Add the stock and tomato sauce. Stir in the sausage and parsley. Simmer until heated through, about 10 minutes. Serve with warm bread.