Bateta jo Shaak / Spicy Potatoes in Tomato Sauce

I just realised, this is my 201st post!
And Chachi's Kitchen will be 1 year old on 13th November more importantly:
Chachi (my mom and rasoi teacher) will be 75 on the 27th of November. So get ready for some celebratory recipes.

12 small new potatoes; quartered (leave the skins on)
1 tblspn oil
½ tspn cumin seeds
½ tspn mustard seeds
3 large tomatoes; blanched, peeled and crushed
2-3 cloves garlic; crushed
1 ½ inch ginger; grated
2-3 green chillies; chopped fine
¼ tspn tumeric
2 tspn coriander / cumin powders
salt to taste
Coriander leaves and stem; chopped

1. Heat the oil in a saucepan, add the cumin and mustard seeds. As soon as the pop, the potatoes, fry them until they are almost cooked
2. Add the tomatoes, cook for a few minutes, add the garlic, ginger and chillies, mix and cook for a further 5 minutes, add the salt, tumeric, coriander and cumin powders, mix and cook until the potatoes are cooked.
   
3. Garnish with the chopped coriander
   
4. Serve with hot puries