Put a large pot over a medium-high flame and heat the oil. Add the sausage and break it apart with a wooden spoon as it cooks. Cook until browned, about 7-10 minutes.
Add in the onions and garlic and red pepper flakes if you’re using them. Cook until the onions are softened, about 5 minutes.
Add in the peppers and cook until softened, about 10 minutes.
Add in the tomatoes, water and Bouillon cubes. Bring to a boil and cook for 10 minutes.
Serve with crusty bread and a sprinkle of grated cheese.