Put the dried mushrooms in a heatproof bowl, pour over the boiling water to cover and set aside to soak for 15 minutes.
Meanwhile, heat the oil in a large flameproof casserole dish. Add the onions and garlic and cook, stirring, for 5–7 minutes, until the onions are soft and just starting to brown.
Drain the soaked mushrooms in a sieve set over a jug to catch the soaking liquid. Line the sieve with paper towel and strain the liquid to remove any grit.
Add the liquid to the onions, along with the red wine and sage. Bring to the boil, then reduce the heat. Add the fresh and soaked mushrooms and stir for 3–4 minutes until the mushrooms start to give off their juice.
Stir in the tomatoes with their juice, the sugar and seasoning to taste. Cover and simmer for 12–15 minutes until the sauce thickens and the tomatoes start breaking down. Meanwhile, preheat the oven to 190 degrees C.
While the sauce is simmering, add the pasta to a large saucepan of boiling water and cook for just 5 minutes until the pasta is just beginning to become tender (do not cook until tender).
Drain the pasta well, then stir it into the sauce along with the artichokes. Taste and adjust the seasoning, if necessary. Place the casserole dish in the oven, uncovered, and bake for 20 minutes until the pasta is tender. Serve the bake straight from the dish.