Heat the oil in a large soup pot or Dutch oven over medium heat.
Add the onion and sauté for about 3 minutes, stirring occasionally until it is starting to soften.
Stir in the garlic and cook for an additional 2 minutes until fragrant.
Sprinkle in the curry powder and cinnamon, followed by the carrots. Cook for 3 minutes, stirring frequently to release the spices’ aroma.
Mix in the tomato paste, stirring to coat the vegetables evenly.
Add the lentils, coconut milk, and broth, then season with salt and pepper to taste.
Bring the mixture to a gentle boil, then reduce the heat to low. Cover and simmer for 25 minutes, stirring occasionally.
Stir in the lemon juice just before serving to brighten the flavors and season with salt and pepper.
Ladle the soup into bowls and top with a dollop of yogurt, a sprinkle of almonds, fresh cilantro, and a wedge of lemon if desired.