Cook the lentils
in boiling water for about 1 hour until tender then
drain and set aside.
Heat the oil
and fry the mustard seeds, asafetida,
fenugreek and cumin seeds, red chili and curry
leaves until the mustard seeds start crackling.
Add the green chilies and
vegetables and fry for 2 minutes. Add the
tamarind juice, water, sambar powder, turmeric
and salt, cover and
simmer over a low heat until the vegetables are
tender.
Stir in the
cooked lentils and simmer for 5 minutes. If the
sambar needs to be thickened, blend the rice flour
with the water, stir it into the pan and simmer for
a further few minutes.