For the Chinese cabbage vegetables, wash the Chinese cabbage and cut into strips (as for salad).
Sweat the oil with the flour in a large pot and add the Chinese cabbage strips. Add salt and remove from the hot stove. Cover the pot and let stand for 2 minutes, this will cause the vegetables to collapse and combine with the roux when stirred.
Season with pepper, cumin and garlic and mix with the potato pieces and let the Chinese cabbage vegetables steep for another quarter of an hour at low heat.