1. Soak the dried beans in water overnight, then drain off remaining water and rinse.
2. In a large stockpot, cook the onion in oil over low heat until just beginning to soften for about 4 minutes.
3. Stir in garlic and cook for 1 minute.
4. Increase the heat to medium, add lamb and cook for 3 to 4 minutes.
5. Stir in carrots and celery and cook for 1 minute.
6. Stir in tomatoes and season with parsley, thyme, oregano, freshly ground pepper and salt to taste.
7. Add beans and broth to the pot.
8. Bring to a boil, boil for 5 minutes, then reduce heat to medium-low.
9. Simmer covered for 1/1/2 hours or until beans are tender.
10. Rinse spinach and then place in a saucepan.
11. Place over medium heat and cook until wilted. This will only take a short time and you will not need to add more liquid to the pan.
12. Top each serving of soup with wilted spinach and crumbled feta cheese and serve.