1. In a 3- to 4-quart pan over high heat, bring about 2 quarts water to a boil. Add onions and cook 5 minutes. Remove with a slotted spoon and let stand until cool enough to handle. Slip peels from onions.
2. In a 5- to 6-quart pan over medium-high heat, stir chicken and sausages in oil frequently, until both are starting to brown, about 5 minutes. Add mushrooms and garlic and stir often until mushrooms are limp, about 5 minutes. Add wine, tomatoes, tomato sauce, oregano, artichokes, and onions; bring to a boil.
3. Reduce heat to maintain a low simmer. Partially cover pan and cook until sauce is thickened, about 45 minutes. Add salt and pepper to taste.