Boil the lentils in a large saucepan. A white foam will form on the surface of the water. Skim off this foam.
Add turmeric, cumin and tomatoes and stir into the lentils.
Reduce the heat and simmer for 40 minutes with the lid on, until the lentils are soft.
Stir chili peppers, salt, chili seasoning and cilantro into lentils and remove from heat.
Heat oil in a small frying pan. Cook the garlic and onions until golden brown. Then add the cashews and raisins and roast until the cashews are a little toasted.
Mix with the lentils and serve.