Put the onion, garlic and ginger in a
food processor and blend to a purée.
Heat the oil in a large pan and fry the
onion purée for 20 mins until starting
to colour, stirring frequently. Add the
cardamom and coriander, and fry a
few mins more.
Stir in the lamb, fry until it starts to
brown, then pour in the stock. Add
the chilli, tomato purée, coconut and
curry leaves, then cover and simmer
for 1 hr. Add the aubergines and
cook for 30 mins more until the lamb
and aubergine are tender.
Meanwhile, make the potato topping.
Boil the potatoes whole in their skins for
15-20 mins until just tender, then drain
and cool. Also, wilt the spinach in a hot
pan. Cool and squeeze in your hands to
remove as much water as you can. Peel
and thickly slice the potatoes, then toss
with the oil, tamarind, turmeric, cumin
seeds, curry leaves and seasoning.
Stir the spinach into the curry and
spoon into one extra-large or two
regular-size ovenproof dishe(s). Pile the
potatoes on top and lightly press down.
Dish can now be frozen, see below.
If eating straight away, heat oven to
160C/180C fan/gas 4 and bake for
50 mins-1 hr (add 30-40 mins if using an
extra-large dish). Serve with chutney
and raita or an Indian salad made with
chopped red onion, coriander,
tomatoes, cucumber and lemon juice.