Brisket Cooked with Sauerkraut

My daughter loves German food, so we came up with this:

4 lbs beef brisket
1 onion thinly sliced
2 tblsp olive oil
1 1/2 cup sauerkraut
1 1/2 cup applesauce
1 1/2 cup German white wine
1 can chopped tomatoes, with juice
1/4 cup cider vinegar
3 leaves fresh sage
1 bay leaf
1 teasp ground cumin
1 tblsp grainy mustard
1/2 teasp ground pepper
2 tblsp cornstarch or potato starch

Brown brisket in dutch oven then set brisket aside.  Saute onions in olive oil until brown in the dutch oven, then add sauerkraut, applesauce, white wine, tomatoes, vinegar, and seasonings.  Put brisket on top and press down to submerge.  Cook barely at a simmer for 4 hours or until tender, turning a few times.  Strain out solids and boil liquid until reduced by half.  Add 2 tblsp cornstarch or potato starch mixed with a little cold water to thicken the sauce if desired.  Slice meat and return meat and the sauerkraut and onions to the sauce.  Add a little fresh vinegar if needed.