Heat 1 tablespoon olive in a large saucepot over medium-high heat. Add the chopped onion, celery, carrots, and smashed garlic. Season with salt and pepper and saute until the vegetables are translucent, about 5-6 minutes.
Add 1 teaspoon dried thyme, 1 teaspoon dried oregano, 1 bay leaf, 1 teaspoon red pepper flakes, 1 parmesan rind, 28 ounces canned cannellini beans with their liquids, and 4 cups chicken or vegetable broth. Cover the pot and bring it to a boil. Reduce the heat to medium-low and continue to simmer for 20 minutes.
Add 6 cups spinach to the soup and cook until wilted, about 2-3 minutes. Add 8 ounces cooked orzo and cook for another 2 minutes. Season the soup with the juice of 1 lemon, salt, and pepper.
Portion the soup into bowls and top with grated parmesan, fresh parsley, and fresh dill. Serve hot.