Using your hands, form small meatballs with the chicken Italian sausage. Try to make them the same size to ensure even cooking.
Drizzle olive oil in a pot over medium heat.
Add meatballs to the pot. Do not overcrowd the pan and do not let the meatballs stick together. Cook until golden and remove from pot. This may have to be done in batches.
Add onions and celery to the same pot. Cook until just softened (approximately 5 minutes).
Add garlic to the pot and cook for 1-2 minutes more.
Add thyme, dried oregano, and crushed red pepper flakes to the pot. Stir and pour in the chicken broth.
Stir orzo and cannellini beans into the broth. Return meatballs to the pot, and toss in the bay leaves.
Bring to a boil, place the lid on the pot, reduce heat to medium low and simmer for approximately 10 minutes or until orzo is tender.
Add kale to the soup followed by lemon juice. Start with the juice of one lemon and as more as needed. Season with salt and pepper to taste.
Place the lid back on the pot and simmer until kale is just wilted.
Serve warm.