Prep the veg: Peel and finely chop the onion, garlic and ginger. Cut the carrots and peeled celeriac or parsnip or potato into small bite-sized pieces so they will cook quickly.

Fry the veg: Add 1 tablespoon of oil to a large pot and allow it to heat up for 1 minute. Then add the onions, ginger and carrots. Add with 1 teaspoon of salt, and cook on a high heat for 3 minutes or until the onions are starting to brown. Add the garlic, celeriac or parsnip or potato and another teaspoon of salt and cook for a further minute, stirring occasionally.

Sweat the veg: Add 5 tablespoons of water, put the lid on the pot, turn the heat down to medium and leave to cook for 5 minutes, stirring occasionally. If any of the veg start to stick, add another few tablespoons of water to deglaze the pan.

Add remaining ingredients, then boil and simmer: Add the chopped tomatoes, red lentils, vegetable stock or water, curry powder and ½ teaspoon of black pepper, and stir well. Turn the heat up high and bring to the boil with the lid on. Stir regularly, as you don't want any of the red lentils sticking to the bottom of the pot and burning. Once boiling, reduce to a simmer and leave to cook for 20 minutes (or until the red lentils are soft, broken down and cooked through), stirring regularly.

Add spinach: Remove the soup from the heat, add the washed fresh baby spinach (or similar green) and stir well.

Taste and season: Check the seasoning, and add more salt and pepper if necessary. We love this soup chunky, but if you prefer it smooth then blend using an immersion blender before serving.