[Lardman]

For anyone who wants to play along at home this is where I am so far.

1 x red lentils
3 x water (previously using 4x but it was taking an hour to reduce)
1 onion fine diced
2 tsp ginger puree
1 tsp garlic puree
1 tsp chilli powered
2 tsp curry powder
1 tsp coriander power
1 tsp cumin powder
1 tsp turmeric
2 tsp salt
1 tblsp tomato puree

Soften onions in oil
Add garlic & ginger
Add spice mix fry until fragrant
Add tomato puree
Fry off until oil separates
Add lentils
Add water
Add salt
Simmer until cooked.

What this gives is so much better than the lentils in spicy dish water stage I was at. The texture is about right, there's a good balance between sweet, savoy and heat with the onions and tomato puree. It's nice enough to eat, but it lacks the depth of flavour and richness I'd like.

[hasbeans]

You could try adding a tadka to your current recipe.  A bit of ghee/butter at the end should help with richness and the late addition of spices the depth of flavour.

https://www.seriouseats.com/what-is-tadka-tarka-chaunk-chhonk-baghaar.

[Plot 1 Problems]

The only thing I'd do different is to use fresh garlic and ginger, but i appreciate that if you don't use it often it'll go to waste in the cupboard.

[mumofstig]

Stirring in some Garam Masala spice mix towards the end, is the way to go IMO.

[Blewit]

Pre-soaking the lentils for half an hour drastically reduces cooking time. A splash of Thai fish sauce can't be tasted as such but adds depth of flavour.

[Lardman]

Not sure about the fish sauce ...  I did consider a tarka but was trying to avoid the James Martin solution to all things (aka add more butter  ) I'll give it, and everything else suggested a go as I want to get this sorted so I can batch it for the freezer.

[New shoot]

Garam masala is very good at deepening flavours and is best added towards the end of cooking.  Buy a decent brand that contains a proper mix, not just the cheaper spices like coriander and cumin.  The East End one is good.

If you can get hold of it, black cardamom is also good for depth of flavour.  It works really well with meat or dhal.  Add it with the water when you get to the simmering stage.

If you like coconut, it is an alternative source of richness to butter.  A small amount of coconut cream off a block towards the end of cooking will add a creamy texture, but it has to said that it has more saturated fat than butter.  I have a tin of ghee I keep in the fridge where it lasts forever (well nearly).  Even for a big pan of dhal, I only add a tablespoon or so to start the frying process at the start, instead of the oil you use.

[Lardman]

Come on Shoots, it's me - there's black cardamon is in the cupboard, along with green and powdered   I can also confirm ghee doesn't last forever    The whole coconut in curry things is a hard pass though.

[Lardman]

The results are in from another batch.

Cardamon gets lost in the other flavours.
Garam masala gives an overpowering sweetness but does add to the depth.
A knob of butter makes a huge difference.
Roast cumin seeds weren't a good idea.

Next batch I plan on reducing the tomato puree and garma masala and adding a fresh chilli towards the end.