Boil the potatoes: peel and cut the potatoes into small pieces. Then, boil the potatoes.
Chop: the onions and tomatoes into small pieces.
Mix: in a big bowl, add and mix together the potatoes, onions, tomatoes, coriander, garlic and ginger paste, lemon juice, cumin powder, salt and chilli powder.
In a pan: heat the mustard oil in a pan and add the fenugreek seeds. Fry the fenugreek seeds until they turn brown.
Add: turmeric powder into the pan once the fenugreek seeds turn brown. Stir for a few seconds and then pour the oil and seeds into the potato mix. Mix well together and the aloo sandheko is ready.