Heat the oil in a large saucepan over medium-low heat. Add the garlic and sauté until fragrant, about 1 minute. Add the onion and sauté until softened, about 3 to 5 minutes. Add the curry powder and salt, and sauté over medium heat until the mixture begins to brown.
Add the red lentils and sauté for 1 minute. Add the water, bay leaves, and cinnamon stick. Bring the mixture to a boil, turn the heat down to low, and simmer for about 20 minutes, stirring occasionally.
Add the chopped tomatoes, and simmer for another 10 minutes, until thick. The lentils should be soft and the consistency just liquid enough to pour.