Heat olive oil in a large pot over medium heat. Cook sausage, breaking into crumbles, until browned, about 5 to 6 minutes. Remove from the pan and set aside.
Next, add onion, garlic, carrots, and celery. Sauté for 5 minutes, until softened. Stir in Italian seasoning, red pepper flakes, and add back the sausage.
Add broth and drained beans. Bring to a simmer, then reduce the heat and cook for 10 minutes.
Stir in the kale and simmer for another 5 minutes until wilted.
Finish with lemon juice and adjust seasonings if needed. Serve hot. Enjoy!
Notes
Like many soups, this one is meal-prep and freezer-friendly! Let it come to room temperature, and transfer to a glass container. Store in the fridge for up to three days or in the freezer for up to three months. Your future self will thank you!