Start by cutting the chicken into bite-sized chunks. Dice the onion, carrots, and celery into 1/2-inch pieces, and mince the garlic.

In a large pot, heat olive oil over medium heat. Add the diced onion, carrots, and celery, cooking for about 6 minutes until they are softened and fragrant.

Stir in the minced garlic, salt, smoked paprika, and cumin. Cook for an additional minute to bloom the spices.

Pour in the chicken chunks, rinsed green lentils, fire-roasted tomatoes with their juice, and chicken broth. Stir everything to combine and bring to a gentle boil.

Once boiling, reduce the heat to medium-low. Partially cover the pot and let it simmer for about 25 minutes, stirring occasionally.

Just before serving, stir in the fresh spinach and cook for an additional 1-2 minutes until wilted. Adjust seasoning if necessary.