Wash the split peas well, rinse it a few times until the water runs clear. You can also soak your dhall for a few hours before boiling but not necessary. Add dhall, turmeric and some salt with 2 cups of water to a saucepan and cook until soft, I prefer mine really mushy but if you are happy with it a little grainy that's fine too.
In a separate pan heat oil, add the cinnamon stick, bay leaf, mustard seeds and cumin. As soon as the seeds start to splutter add your onion, dry chilli and curry leaf. Sauté until onion is a little brown.
Add garlic, curry leaf and dry chilli, fry for a minute. Add masala , chilli powder and garam masala. Fry for a minute and then add the tomato. You can add a few drops of water, cover and cook on a low heat until tomatoes are cooked.
Add the cooked split peas and let it simmer on a low heat until dhall thickens, you can check the consistency as it cooks and add more water based on your preference.