In a large soup pot, heat the olive oil and fry the bacon until it starts to brown. Add the garlic, onion, carrots, celery, oregano, and basil. Cook over medium heat for 10 minutes, or until vegetables start to soften, stirring occasionally. Add tomatoes, potatoes, chickpeas, stock and bay leaves. Season with salt & pepper. Bring to a boil and reduce heat to a high simmer for about 20 minutes, or until potatoes are done. Add the pasta shells and cook until they are done, about another 10 minutes. Turn off heat and stir in spinach leaves. Serve garnished with Parmesan.