2 tbsp olive oil
2 onions, finely chopped
leaves from 2 sprigs fresh thyme
4 carrots, finely diced
3 garlic cloves, finely chopped
1 red chilli, seeded and finely diced
2 teaspoons yellow mustard seeds
6 tomatoes, roughly diced
8 oz red lentils
4 pints hot vegetable stock
8 tbsp 0% fat Greek yoghurt
finely grated zest and juice of 1 lemon
sea salt and freshly ground black pepper
Heat the oil in a large pan and cook the onion, thyme and carrots for about 3-4 mins. Add the garlic, chilli and mustard seeds and cook for another 2 mins.
Stir in the tomatoes, lentils and stock and bring to the boil. Reduce the heat, cover and simmer gently for 30 mins until the lentils are tender and easy to crush.
Mix together the yoghurt, half of the lemon zest and season to taste. Squeeze the lemon juice into the soup and season with salt and pepper.
Ladle the soup into warmed serving bowls and serve with a spoonful of the lemon yoghurt, scattered with the remaining lemon zest and ground black pepper.