Start by peeling and slicing the onions and garlic. Peel and cut the potatoes into 5-cm or 2-inch cubes.
In a skillet or pan, heat the oil. Once oil is heated, add in the onions. Cook for about 2 minutes or until a little translucent.
Next add the minced ginger and garlic to the pan. Stir and cook for another minute. Then add the curry leaves. Clear a small section of the pan and then add the mustard seeds. Roast for 30 seconds or until they start to pop.
As soon as they start to pop, add the potatoes. Stir and cook for 1-2 minutes. Then add a little water and cover. Cook for about 15 minutes or until potatoes are cooked up to 75%.
Occasionally check on the potatoes and add a little water if they are sticking to the pan.
While potatoes are cooking, shred the cabbage rather thinly. Cut the tomatoes in quarters then slice thinly.
Add the cabbage. Cover and let wilt a little. Next stir and mix the cabbage with the potatoes. Then add in the tomatoes and stir. Add the thyme leaves.
Add salt to taste and a little water if needed. At this stage, add the dried chilli. I am only adding it at the final stage of cooking for a subtle kick. If you like it a lot more spicy, you can add the chillies together with the potatoes.
Then cover again and let the cabbage cook for another 5 minutes or until the cabbage and potatoes are done. The cabbage should still have a slight crisp to it.