Dice the onion, celery and carrot and mince (not crush) the garlic.
Add the olive oil to a large saucepan over medium heat. Add in the chopped vegetables and saute for 5-10 minutes until they soften, turn down the heat if they start to brown at all.
Rinse and check over your lentils (no one enjoys consuming stones) and then add to the pot with the stock. Bring to a boil and simmer for about 30 minutes until the lentils are soft.
Add the ground cumin and lemon juice and season with salt and pepper.
If the soup is too thick for your liking add a bit more water.
Dish up in bowls with a healthy smattering of coriander and some chunks of crusty bread on the side to mop up all the tasty goodness.