This is my mum's recipe, and it's great.
1 cup red lentils/split peas
2 1/2 cups water
1 tsp turmeric
1/2 tsp cayenne
1 tsp salt
Bring all to the boil, reduce heat and simmer until consistency of thick gravy.
While that is happening, saute in frying pan:
3 tbls butter
1 large onion
1 tsp whole cumin seeds
10 whole cloves
5 whole black peppercorns
Fry slowly until onion well browned, and stir into lentil mix.
It's very nice (I think) and usually surprises people who think they don't like dahl. Be careful of the whole spices after (they're not to be eaten)