Heat the olive oil in a large pot over medium heat. Add the chopped onion and sauté until translucent, about 5 minutes.

Add the minced garlic and cook for another minute until fragrant.

Add the diced potatoes to the pot and sauté for a few minutes.

Add the chopped kale to the pot and stir until it starts to wilt.

Pour in the vegetable broth and bring the mixture to a boil.

Reduce the heat to low, cover the pot, and simmer for about 15 minutes, or until the potatoes are tender.

Add the cannellini beans and dried thyme to the pot. Season with salt, pepper, and red pepper flakes (if using). Simmer for another 5-10 minutes.

Taste and adjust the seasoning as necessary.

Serve the kale soup hot, optionally topped with grated Parmesan cheese.