Heat olive oil in a 6-quart dutch oven over medium high heat. Add diced onion, carrot and celery. Cook for 8 to 10 minutes, until onion is translucent. Add garlic and cook for 1 minute.

Pour in vegetable broth and bring to a simmer. Once simmering, add in chickpeas, salt, pepper, oregano and orzo. Cook for 8 to 9 minutes, until orzo is al dente.

Meanwhile, add lemon juice and tahini to a small bowl and whisk together until well combined. After orzo is cooked, add lemon and tahini mix to the soup. Remove from heat and stir in baby spinach and dill. Continue stirring until spinach is wilted, about 2 to 3 minutes.

Serve. Bring leftovers to room temperature and store in an air-tight container for up to 5 days in the refrigerator.