Deliciously nutritious and comforting soup really doesn't get any better than my mildly-spiced easy crockpot tomato lentil soup. It's vegan and gluten-free too!
Add all the ingredients to the slow cooker bowl, give everything a stir, put on the lid, and then set the timer for six hours (on high).
On the hob
Heat the oil in a large heavy-bottomed pan over a high heat, and sauté the onions for 4-5 mins, until they start to become translucent.
Add the spices, and continue to fry for another minute, stirring continually.
Stir in the lentils, herbs and vegetable broth, cover the pan, bring to the boil, then reduce the heat to medium, and cook for 10 mins, until the lentils have softened.
Reduce the heat to low, and add the rest of the ingredients. Stir well, cover the pan again, and simmer for 20 mins or so, stirring occasionally, until the lentils and onions are soft.