This very exotic dish is straight from Palakkad and uses ripe mango. There is a version that uses raw mango too. The recipe is in this blog under the title Mango Kadhi. The ripe mango version is really tasty provided you like sweetness in your curry.
There has been a lot of debate (especially in India) on whether a fruit can be included in a main meal. The jury is out as the opinion is divided amongst experts. It did not bother me too much as I generally do not like a sweet curry with my rice. My dad used to love this and often requested it whenever he visited me. And so do all my staff at home. Rather than deprive them of the pleasure, I sometimes prepare this for them.
This is a very traditional recipe with very little, but an interesting mix of) spices.

Ingredients
1 large, ripe mango
500 gms ash gourd (safed peta, poosinikkai)
1 tsp turmeric powder (haldi, manjal podi)
1 tsp chili powder
250 ml vegan butter milk (thin yogurt)
Unrefined salt to taste
For The Masala
1/2 coconut, grated
4-5 dried red chilis
1/2 tsp fenugreek seeds (sabut methi, venthiyam)
For The Tempering
1 tsp mustard seeds (sarson, kadugu)
1-2 dried red chilis
1 sprig curry leaves
Method
Wash and cut the mango into 2″ cubes
Place it in a vessel and add salt, turmeric powder, chili powder and enough water to immerse the vegetable and fruit
Cook til the ash gourd is done
Meanwhile, grind the coconut, fenugreek seeds and red chilis (mentioned under ‘For The Masala’ in a little of the buttermilk
Pour this into the vessel with the mango and ash gourd
Add the remaining butter milk and mix well
Bring to a boil
Remove from flame and set aside
Heat a wok and add mustard seeds
When they begin to splutter, add the red chilis
Roast for about 10 seconds (the chilis should not burn)
Add this to the cooked ash gourd and mango
Garnish with curry leaves
Serve hot with steamed red/brown/millet rice
Enjoy!