Aloo tamatar (potato-tomato)

It's called Aloo-Tamatar but I usually end up using any root veggies (except sweet potato) I might have on hand. This time I used a combination of turnips, carrots and potatoes. This quick and tangy recipe is from V's mum.
Serves 4-5

3 cups of cubed (1 inch) potatoes, turnips and carrots
1 1/2 tsp cumin seeds
3 green chillies chopped
3 small tomatoes
1 1/2 tsp coriander powder
2/3 cup of yogurt
1/4 tsp turmeric powder
1 tsp garam masala

Heat oil and add cumin seens. As soon as you can smell them roast, add tomotoes, green chillies, salt to taste, turmeric, coriander powder and garam masala. Cook until you see the oil seperating out. Add cubed root veggies and stir to mix. Bring to a simmer. Take 1 tbsp of the simmering sauce and whip the yogurt with it. Doing this before adding the yogurt prevents the yogurt from seperating when added to the hot sauce. Add the whipped yogurt to the sauce-veggie mix. Cover and cook until root veggies are done (~10 mins). Garnish with fresh coriander.