Drizzle some oil into a medium pot or Dutch oven set over medium-high heat, squeeze the sausages out of their casings and cook, breaking up with a spoon, until no longer pink.
Add the vegetables and cook for 3-4 minutes, until starting to soften.
Add the stock, bring to a simmer and cook for 10-15 minutes, or until the vegetables are tender. If you like, stir in some cooked pasta, lentils, kidney beans or chickpeas, and some kale or spinach, stirring until it wilts.
Serve with Parmesan cheese grated on top.