Finely chop the onion
Mince the garlic
Juice 1 lemon
Place the lentils, onion and water in a large pot and bring to the boil
Reduce the heat and skim off any scum or foam with a slotted spoon
Add the bulgur, partially cover and cook until done according to the packet instructions
Add the garlic and tomato purée, mixing well
Add the lemon juice, salt and pepper to taste
Place soup in a large serving bowl
In a small skillet, melt the butter until it sizzles
Remove from the heat and stir in the mint
Pour over the soup and serve