Rinse 1 cup of toor dal in a colander until the water runs mostly clear.

Soak the rinsed toor dal in enough water to cover it for 60 minutes, then drain.

Roughly chop the 3 tomatoes.

Combine the soaked toor dal, chopped tomatoes, 1/4 teaspoon ground turmeric, 1/2 teaspoon salt, and 5 cups water in a large saucepan.

Bring the dal mixture to a boil over medium-high heat.

Reduce the heat to low and simmer for about 30 minutes, stirring occasionally, until the dal is very soft.

Blend the cooked dal briefly with an immersion blender if a thinner, smoother consistency is desired.

Heat 2 tablespoons neutral cooking oil in a small frying pan over medium heat.

Add 1/4 teaspoon mustard seeds and 1/2 teaspoon cumin seeds; cook until they splutter.

Add 4 to 5 curry leaves, 1/4 teaspoon fenugreek seeds, 1 cinnamon stick, 3 dried red chilies, and 3 cloves to the hot oil.

Stir the tadka for 30 to 60 seconds until fragrant, taking care not to burn the spices.

Pour the hot tadka into the simmering dal and stir to combine.

Stir in 2 tablespoons coriander leaves leaves and adjust the salt to taste.

Ladle the dal into bowls and serve with lemon wedges.