Cut the potatoes in 1" pieces. Cut the onion thin length wise. Mince the garlic.
Put oil in a karahi (skillet or bowl). Put the dried red chili, coriander seeds in the oil and let it splutter. Put the onions in the karahi and fry till red. Put the green chili and the garlic.
When the onions turn red put the potato and fry for 3-4 minutes.
One by one put salt, jeera-dhaniya powder and 3/4 cup of water. Cover it with lid and simmer. Cook the potatoes until they are soft. Chokha does not have curry so no water should be there.
Put the amchur powder and mix it with the potatoes.
