Rinse the chicken quarters and pat them dry. Place in a heavy deep pan over a medium high heat and add the oil. Cook for 5 minutes or so , turning , until lightly browned all over.
Add the garlic, ginger, garam masala,bay leaves, onion and lemon slices. Cook until fragrant.
Add 8 cups of water and bring to the boil. Skim off the scum as it rises to the top. Lower the heat and simmer, partially covered, for 2-3 hours, adding more water as required.
Strain the soup and discard the solids. Stir in the mint and season to taste with salt, pepper and lemon juice.