1. Preheat the oven to 190 C.
2. Spread the quartered tomatoes on a baking sheet and sprinkle with sugar, salt and pepper. Drizzle with 1tbsp olive oil and bake in the oven for 30 minutes. Let the tomatoes cool a little and then tip them into a deep bowl and roughly blend with a stick blender.
3. Heat 1 tbsp oil in a large saucepan. Add the garlic and spices and stir well for a couple of minutes then add the tomato mixture. Bring to a simmer, then cook, for 10 minutes before adding the lentils and salt. Pour in 800ml water, then bring the mixture back to a simmer for 20 minutes or so. The lentils should be cooked and the dhal thickened by now. It will thicken further if you leave it to stand for a few minutes. Adjust the seasoning
4. Meanwhile, to make the tadka, heat the oil in a frying pan, add the spices and cook for a couple of minutes, stirring now and then, until the mixture smells toasty. Add the shallots and cook, stirring often, for about 10 minutes or until they are soft and lightly browned. Season with a little salt.
5. Pour the dhal into a serving dish, top with the onion tadka and serve.
Recipe courtesy of Isle of Wight Tomato Dhal