Heat the olive oil in a large pot over medium heat. Add the onion, carrots, and celery with a pinch of salt and cook until softened and starting to color, about 6–8 minutes. Add the garlic, cumin, smoked paprika, and thyme and cook for another 30 seconds until fragrant.
Stir in the rinsed lentils, diced tomatoes with juices, and chicken broth. Add the bay leaf and bring to a simmer. Reduce the heat, cover partially, and simmer gently for 25–30 minutes, or until lentils are tender.
Add the shredded chicken and simmer 5–8 minutes until heated through. Season with salt, pepper, and red pepper flakes if using. Remove and discard the bay leaf.
Turn off the heat and stir in the lemon juice. Ladle into bowls and garnish with chopped parsley. Serve warm.
Notes
If using red lentils, reduce simmer time to 12–15 minutes as they break down faster.
Mash a cup of cooked lentils against the pot for a creamier texture without dairy.
This soup freezes well—portion into containers for easy lunches.
Use rotisserie chicken to save time and add flavor.