Gather all your ingredients and ensure they are ready for cooking.

Dice the onion, carrots, and celery. Mince the garlic.

In a large pot, heat the olive oil over medium heat. Add the diced onion, carrots, and celery. Sauté for 5-7 minutes until soft. Stir in the minced garlic and spices, cooking for an additional 1-2 minutes.

Add the rinsed lentils and vegetable broth to the pot. Bring to a boil, then reduce heat to low and simmer.

After 25-30 minutes, check the lentils for tenderness. Squeeze in the lemon juice and add the zest. Season with salt and pepper to taste.

Let the soup simmer for a few more minutes, then serve hot, garnished with fresh parsley.