Heat the oil in a deep frying pan and fry the sausages for 4-5 mins until golden brown. Remove and set aside.
Cook the onion in the same pan for 5-6 mins until softened, adding a splash of water if it starts to catch. Add the chickpeas, tomato sauce and stock and bring to the boil. Return the sausages to the pan, lower the heat to a simmer and cook for 5-6 mins until the sausages are cooked through. Scatter the garlic, orange zest and parsley over the stew, then serve in shallow bowls with crusty bread on the side.