Heat oil in a heavy bottom pan. Add mustard, cumin, fennel and dry red chilli and sauté for 30 sec.

Add sliced mangoes and mix well. Add a dash of water and cover the pan and cook for 15 min until the mangoes are cooked.

Now open the pan and add salt, black salt and sugar. Mix well.

Cook for 10 mins until the chutney gets thick and leaves the sides of pan.

Serve or store in air tight container in  fridge.