Heat oil in large non-stick soup pot (or spray) over medium heat. Add onion, cook for 5 minutes. Stir in garlic, ginger, cumin, coriander, fennel and cinnamon; cook, stirring a few times, for 1 minute. Add broth and water and increase heat to high. Bring to boil. Reduce heat to medium-low and bring to a simmer; stir in lentils. Cover and cook until lentils are tender, 30-40 minutes. Check frequently after 25 minutes. OR put ingredients down to water in slow cooker on high for 4-6 hours. OR put it in an electric pressure cooker on Instant Pot and cook for 10 minutes. Use pressure release after another 10 minutes.