Preheat the oven to 300 degrees F and bake sausage links for 25 minutes or until done. Cut the links in half (lengthwise) then cut them at an angle into 1/2 " slices. In a large saucepan, over medium heat, cook the onions until they are almost clear.
In a 4-quart slow cooker, combine all ingredients except ravioli; mix well and cover. Cook on LOW setting for 6 hours or until vegetables are tender. Before serving, increase heat to HIGH setting.
