Wash and chop the vegetables. Dice the onion, carrots, and celery into small pieces. Peel and dice the potato into cubes. Rinse the lentils under cold water.

In a large pot, heat the olive oil over medium heat. Add the diced onion and sauté for about 5 minutes until translucent. Stir in the minced garlic, carrots, and celery, and cook for an additional 3-4 minutes.

Add the rinsed lentils, diced potato, and the can of diced tomatoes (with their juice) to the pot. Pour in the vegetable broth, and sprinkle in the dried thyme, ground cumin, paprika, salt, and pepper. Stir everything together well.

Bring the mixture to a boil over high heat. Once it reaches a boil, reduce the heat to low, cover the pot, and let it simmer for about 30-35 minutes, stirring occasionally.

Taste the stew and adjust the seasoning if needed. If it’s too thick, add a little more broth or water. Serve the stew into bowls and garnish with fresh parsley if desired.