Fried Cabbage & Potatoes (Indian style)

3 T oil                   1 med onion, chopped
1 tsp mustard seed (1/4 tsp dry)
4 lg potatoes, cut to 1/2" cubes
8 c coarsely shredded cabbage
1 tsp minced ginger (1/4 tsp dry powdered)
1/2 tsp cumin                1/2 tsp turmeric
1/2 tsp cayenne            1 1/2 tsp salt
1 tomato chopped (or 1/2 c salsa)
juice of one lemon

-sautee onion in oil with mustard seed until seeds pop
-add potatoes and cook ~5min.
-add cabbage and spices and salt
-cook uncovered ~25min, until tender and golden
-add tomato and lemon juice just before serving