Heat two tablespoons of olive oil in your large pot over medium heat until shimmering and fragrant.
Add the chopped onion and cook, stirring occasionally, until it turns golden and releases a sweet aroma—about 5 minutes.
Stir in the minced garlic and cook for another 30 seconds until fragrant, filling the kitchen with a punchy aroma.
Add the chopped carrots and cook, stirring occasionally, until they soften slightly and begin to caramelize around the edges—about 8 minutes.
Sprinkle in the cumin, coriander, and cinnamon, then cook, stirring constantly, for 1 minute until the spices bloom and become fragrant.
Pour in the vegetable broth, scraping the bottom of the pan to loosen any browned bits, then bring the mixture to a gentle simmer.
Add the rinsed lentils, stirring to combine, then lower the heat and simmer uncovered for about 20-25 minutes until the lentils are soft and the soup thickens slightly.
Taste the soup and season with salt and pepper as needed. Squeeze in the lemon juice for brightness and stir well.
Ladle the soup into bowls, drizzle with a teaspoon of olive oil, and serve hot, garnished with herbs or a swirl of cream if desired.
