Spicy dahl soup recipe

I love Indian dahl soup, and yesterday a friend asked me if I would make some of it for her as she felt under the weather. This is the recipe I used, and is notable particularly because it contains very few of the ingredients you would expect. However at 8pm on a Sunday night it was all I had, and seemed to be remarkably successful nonetheless.

250g split red lentils
2 onions
1 heaped tablespoon garam masala powder
1250ml chicken stock
half a lemon
salt and pepper
oil

Fry the onions in the oil on a low heat until translucent, then add the curry powder and heat through. Stir in the lentils and then add the stock. Cook on a medium heat for about half an hour until the lentils break down, then whiz with a blender. Add a couple of hefty squeezes of lemon juice, and season to serve. If I had any fresh coriander I might have sprinkled some on top, but predictably I didn't.