In a large saucepan, warm olive oil over medium heat. Add the sausage meat and cook until it starts to release its juices. Add the onion and the ground meat and sauté for four minutes. Add the artichokes, fava beans, peas, asparagus, and stir well. Pour in the broth, cover, and bring to a boil. Reduce the heat to low and continue to cook until the favours have blended, about half an hour. Skim off any froth that may develop on the surface. Halfway through cooking season with salt.