In a medium sized bowl, wash the split yellow peas well. Drain off their water and rinse again, repeating until the washing water runs off clear.
Add the split yellow peas and water to a saucepan and bring to the boil. Skim off any foam which rises to the top and discard. Reduce to simmer, cover and allow to cook for 30-40 minutes, or until the lentils are tender. Stir regularly while cooking.
Once cooked, drain off most of the lentil water and break up the lentils using a whisk. Set aside to cool.
While the lentils are cooling, put the oil in a medium, high sided frying pan or shallow saucepan and place over a medium heat.
Add the single sliced clove of garlic to the oil and, very carefully, move it around the pan until it is very lightly browned - don’t allow it to burn. Remove the garlic from the oil with a spatula and set aside on a piece of kitchen towel.
Add the curry leaves to the oil, mustard seeds and cumin seeds and fry for a minute until fragrant. Add the onion and ginger and cook for a few minutes until the onion starts to turn translucent. Meanwhile blend the tomatoes and remaining garlic in a blender until smooth. Add to the onions and cook for a minute.
Add the ground spices to the pan, along with a good pinch of salt and pepper and stir to combine. Add the water, stir and lower the heat to simmer. Allow the sauce to cook for around 20 minutes until the oil starts to rise to the top.
Add the lentils to the sauce and stir well to combine. Allow to simmer for a few more minutes and then remove from the heat.
Top the dal with the fried sliced garlic and the bunch of coriander, torn roughly. Serve with rice or roti.