For all of you who love mango thokku, here's a simple and easy one. Granny Smiths apple is a good substitute for the sour mangoes we get in India. They are basically sour to taste and green in colour unlike the conventional red apples.
Peel Skin of the apple and remove seeds and grate them. Heat oil and fry mustard, asafoetida and fenugreek. Once the mustards pop, add the grated apple, turmeric, salt. Stir well. When the fruit is cooked three forths, add chilli powder. Mix well. When the mixture leaves the sides of the vessel, remove from flame. Wait for the mix to cool before storing it in a container.