Place a stockpot or large dutch oven over medium-high heat and add the olive oil.
Once shimmering, add the sausage, and red pepper flakes stirring occasionally until browned.
Transfer sausage to a plate using a slotted spoon and set aside.
Add the carrots, celery, onion and a pinch of salt and cook until carrots are just beginning to soften.
Mix the garlic in with the vegetables and cook until fragrant. Next, add the stock, bay leaf, and parmesan rind. Bring to a boil.
Once boiling, reduce heat to a simmer and cook until vegetables are softened to your liking.
Finally, add the beans, sausage, and kale to the pot and simmer for another 5-10 mins.
Season with salt and pepper to taste.