It involves soaking the lentils, bringing the lentils to the boil,, skimming off the froth, addign turmeric and then simmering until the right consitency. Then you stir in the fried up tarka of cumin, chillies and asafoetida (and onions and garlic if you can be bothered).
I think you need quite a bit of salt to be honest.
I am constantly on a quest for the 'right' tarka dahl recipe. It really irritates me that I have about a dozen recipes for it and they are all different, including the fact that no-one seems to be in agreement about exactly which type of lentil/pulse I should be using.
I refuse to try one until I am sure it's the right one.
Actually I did try one, a few years ago, and I had okay but underwhelming results the same as you.
I make a chuck it all in the slow cooker one and it is so delicious I eat it for 3 days in a row. It's a recipe in my head, from making loads of different ones from youtube.
I use a cup of yellow yellow split peas, 1/4 cup each of red lentils, mung dhal, chana dhal, 1 can chopped tomatoes, garlic paste, ginger paste, green chilli paste (all to taste) about a pint of water (I add more during cooking if it gets too thick or until all pulses are soft (some dissolve entirely), salt, turmeric and I use chana masala spice powder from Asian shop. When it's all cooked I add a tin of coconut milk and big handful of chopped corriander.
Sorry it's not a real recipe but you could experiment a bit like I did and eventually you will make one that is a keeper
Fry onion, garlic and chopped green chilli. Add turmeric, cumin seeds, grama massala and mustard seeds. Add red lentils and a bit of water (not much at this point!). Cook a bit. Add a tub of coconut cream and cook some more. Add loads of coriander. You'll probably need to add more water but don't over do it. Add loads of pepper and more salt than you'd expect to need. Beat it a bit, so it gets smoother.
Fry onion in half moons, sliced garlic until brown. Add mustard seeds, cumin seeds and chilli flakes. Stir into the lentils just before serving. Add loads more coriander on top.
my recipe is boiled red lentils, then add onion, salt, turmeric and two garlic. then when consistency of porridge add cumin seeds and add some fried garlic, i normally fry the garlic til black. it is delicious
Story onions, ginger, garlic. Add whatever spices you fancy or a curry powder and fry a bit more. Add red lentils and make sure they are coated in everything. Add water and a veg stock cube and simmer for about 20 mins. Add frozen spinach and some of that solid coconut stuff that comes in little individual packets. DH spends a lot of time in India and he says my Dahl is the best ( well he has to really)