Peel and dice the onion, celery, and carrot, then sauté them in a pan with a drizzle of oil. Meanwhile, remove the casings from the sausages and add them to the sauté pan. Brown them well, breaking them up with a wooden spoon until they form irregular lumps. Add the rosemary needles, parsley, and a few finely chopped sage leaves, then one or two whole bay leaves and the white wine. Cook over high heat for five minutes, then cover with a lid and simmer for about twenty minutes over very low heat. Cook the ravioli in boiling salted water, drain, and transfer them to the pan with the sauce. Stir. Serve immediately, garnished with a generous sprinkling of freshly ground pepper.