Lentil Soup with cumin

This is simple, exoctically spiced and very satisfying-it also passed the JP test!

4 tbsp olive oil
1 large onion, thinly sliced
4 cloves of garlic, thinly sliced
1 1/2 teaspoons cumin seeds, roughly ground
250g red split peas-or anoy other lentils will work
1.75 litres cold water
250 grms spinach or chard -finely chopped and braised quickly with olive oil
1 lemon quatered
sea salt and black pepper

In a large saucepan, heat the olive oil over a medium heat.  Add the onion with a pinch of salt and cook for about 10 minutes, stirring occasionally until sweet and soft.  Now add the garlic and cumin and fry for another minute, followed by the lentils and water.  Bring to the boil, turn down the heat to a gentle simmer, and cook for about 20 minutes or until the lentils are soft.  Remove from the heat and blend until almost smooth.  return to the pan with the cooked spinach, and seasonw ith salt and pepper.  If the soup is too thick, simply add more water and adjust the seasoning.
Serve this soup with lemon or with 150g yoghurt-spiced with 3/4 teaspoon ground cumin and salt, and olives, Harissa (or another chili paste) and bread.