The usual habitat for a chicken pathia seems to be a British curry house; I think this fiery, sweet and sour number with Gujarati leanings should be shown a lot more love.
Soak the tamarind cube in 60ml or ¼ cup boiling water, and mash occasionally.Push the tamarind through a fine mesh sieve; you should end up with around 50-60ml or ¼ cup of paste.
Peel the garlic cloves.
Peel the onion and cut it in half. Roughly chop half of the onion, place it in a mini blender with the garlic cloves and blend to form a smooth paste.
Take the second half of the onion, slice it into 8 wedges and set aside.
Cut the chicken into a 2-3cm (¾-1¼") dice.
Heat two tablespoons of the ghee over a medium-high heat in a 15cm or 6" saucepan, and when it is hot, add the asafoetida and chilli flakes and cook for 30 seconds.
Add in the onion and garlic paste, reduce the heat to medium and cook for 5 minutes; the onions should begin to colour and be fairly dry.
Stir in the turmeric and cumin, then stir.
Add the tomato paste, mango chutney and tamarind, then throw in the bay leaf, cardamom pods and the juice of the lime. Check the seasoning and add salt as required, and allow the sauce to simmer for 15 minutes over a low heat.
Heat the remaining ghee in a 20cm or 12" frying pan over a medium-high heat. Add the chicken and onion wedges, then cook for 10 minutes, stirring occasionally.
Add the sauce to the chicken and crush in the dried fenugreek leaves. Pour in the water, stir to form a sauce and cover with a lid.Cook until the chicken is cooked through, which will take a final 7-12 minutes.