Cured pork rib (kassler rippchen)

1 cured rib roast of pork, or 6 to 8 thick cured or smoked pork chops
1 large onion, sliced
1 tomato, chopped
2 cups boiling water
2 tbsp. flour
1 Tbsp. butter
salt to taste
1/2 cup sour cream

Bake covered at 375 F for 1/2 hour; uncover, add 1 cup boiling water. Continue adding water as needed. If meat is in one piece, roast 1 1/2 to 2 hours; if in chops, roast 40 minutes or until micely browned. Remove meat. Strain or puree the liquid in pan. To gelatinous bits in bottom of roasting pan add blour and butter to make a roux. Stir and cook over moderade heat (on stove top) until flour bubbles; slowly add strained and pureed broth, stirring until smooth. Taste with salt. Turn off heat, add sour cream. Serve with sauerkraut and parsley potatoes or with mashed potatoes and kale.