Hi
this is how I make it - although I have heard you can buy a tinned version!
dry fry onion, garlic, green chillie until soft add grated ginger and tinned toms - medium curry powder and garam masala. meanwhile cook split red lentils with added turmeric. when lentils cooked mix both together. I just tend to chuck everything in so no measurements - sorry! Always tastes better the day after!