Heat a medium pot or Dutch oven over medium-high heat. Add oil to pot and swirl to coat bottom. Add onion, carrot, and celery and saute 3-5 minutes until onion is translucent. Add garlic and cook 1 additional minute until fragrant.
Add chicken broth, ham, lentils, and bay leaf to soup and season with salt and pepper to taste. Bring to a simmer over medium-high heat then cover pot, reduce heat to medium-low, and allow soup to simmer 20-25 minutes until lentils are tender, stirring soup occasionally.
Remove soup from heat and stir in lemon zest, juice, parsley, and spinach until spinach is wilted. Season soup with additional salt and pepper to taste if needed and serve soup warm. Enjoy!
Notes
Storing InstructionsStore soup in refrigerator up to 6 days. Soup may also be frozen up to 2 months.