Ingredients:

4 - medium sized potatoes (cut into quarters)
3 - medium sized baigan (peeled and cut lengthwise)
1 small bunch - spinach (washed and finely chopped)
4 - tomatoes (made into puree)
11/2" piece - ginger
2 - green chillies (finely chopped)
4 to 5 tbsp - oil
1 tsp - cumin seeds
2 1/2 tsp - coriander powder
2 tsp - red chilli powder
1/2 tsp - turmeric powder

sufficient water to make a gravy
salt to taste

Method :

1. Cut the potatoes, brinjals and keep soaked in water. 
2. Heat oil in a kadai or a heavy bottomed vessel. 
3. Add cumin seeds. When the seeds splutter, add the tomato puree, crushed ginger and green chillies. 
4. Saute on a low flame for 10 minutes. 
5. Add coriander powder, red chilli powder, turmeric powder and salt. 
6. Simmer till oil separates. 
7. Add the potatoes, baigan and spinach. Mix well. 
8. Simmer till the vegetables are coated with the tomato mixture, stirring at regular intervals. 
9. Add sufficient water and cook on a low flame till the vegetables are done and the gravy thickens.