All dahls use lentils or other pulses. These can bought cheaply in large bags from Indian supermarkets and represent much better value than buying from your usual supermarket.
My 3 favourite pulses to use are split orange lentils (perhaps the most familiar), 'channa dahl' which are sometimes called yellow split peas (don't be confused - chick peas are labelled as 'channa' in indian supermarkets), and whole lentils with the skins on (basically 'unsplit' lentils) sometimes known as green lentils.
All the lentils I use are dried, you can buy them soft in a tin but they're expensive, heavy, take up a lot of room, and still need cooking anyway to impart flavour.
The basic priciples are the same whichever type of lentil you use. Start using split lentils and then experiment with other kinds once you've tried a few recipes.
With the infinite variety of recipes you can make your dahl to suit the intended use. Many restaraunt dahls are extremely bland and designed to be as inoffensive as possible - they would find many takers around an Indian kitchen table!
This recipe makes about 5-6 side dish portions, it freezes well and can be easily dehydrated / rehydrated.
This recipe is for an aromatic flavoursome accompaniment to a spicy main dish. I've listed just a few other options at the end of the recipe.
Weigh out about 1/2 lb (250gm) of dry split lentils.
Boil a large pan - about half full / a pint and a half - of salted water, add the lentils and 2 tsp of turmeric, bring back to the boil and stir to ensure all the lentils are separated. Cook at high simmer/ low boil and stir occasionally.
Add whole spices to the water (for example 5-6 cloves, seeds from 5-6 cardomon pods - you can leave them in the pods if you prefer, a 2" stick of cinnamon and 2 bay leaves. A 'star' or two of star anise works fantastically well also - technically it's more of a Chinese ingredient but I love the flavour). You can add a split chilli or two at this stage and retrieve it later, or add fresh chillis at the garlic stage below.
If you're worried about the whole spices you can either grind them and add them with the ground spices below or use a 'reusable teabag' which is sold in Japanese food shops or one of those mesh tea dunker things from Ikea. Personally I leave them in, it adds to the adventure, but warn other diners to look out for them.
After about 20-25 minutes on a medium heat the lentils will still be whole and starting to go soft, cooking for longer will reduce the mixture to a thick soup consistency - either if fine. You can also 'blitz' just a portion of the mixture with a wand blender to give you whole lentils in a thick sauce.
While the lentils are bubbling away chop a medium onion finely.
Fry a tsp of cumin seeds in a little oil and add the onions, cook until brown. Add 3 crushed cloves of garlic, a 1" piece of ginger (very finely chopped or grated) and 2-3 chopped green chillis to the onions. Fry for a further minute.
Add ground spices (to suit this recipe I'd use a tablespoon of coriander, a 1/4 teaspoon of red chilli, a tsp of cumin powder - 2 if you didn't add cumin seeds - a pinch of nutmeg and a pinch of asafoetida (hing). You can also add yellow mustard seeds 1-2 tsp for a crunchy 'hotness' or the same quantity of black onion seeds for a 'nutty' flavour. Gently fry the spices, add a little water and fry for a couple of minutes more.
Add the spice mixture to the lentils & water and cook for a further 10 minutes to allow the flavours to mingle. Cook on a low heat until needed.
Alternatively once cooked you can put it in an oven dish and cook in the oven to get a thicker, almost solid, dahl with lots of crunchy bits around the edges (that's how my Mum likes it). Using a wide shallow dish will mean it loses water more rapidly than a taller narrow one.
If at any stage it seems too thick just add more water
- Sprinkle with fresh copped coriander before serving.
- Add dried methi for a 'herby' flavour
- To make 'tarka dahl' cook the onions longer until almost black or garnish with onions deep-fried to a crispy brown and drained just before serving.
- For a darker dahl with a more intense flavour, sprinkle a tsp of garam masala on the surface of the pan after you've added the onion / spice mixture. Allow it to 'melt' on the surface of the water and then stir in (this works better in my opinion that adding it with the other ground spices and frying it - it tends to burn).
- You can add a small piece of creamed coconut (about 1/4 of a block), chopped up, if you want a milder flavour. Alternatively use coconut milk.
- Lemon can be added when you fry the spices
- You can always spice this up and make it as 'punchy' as you like but remember it's intended as contrast to a main course dish
In terms of dehydration I think it works better if you cook it to the thick soup / almost solid stage - a more even consistency makes rehydration more reliable.