01 - Heat the olive oil or butter in a large skillet over medium heat.
02 - Add the sliced leeks and carrot. Sauté for 5–7 minutes, stirring, until the leeks are soft but not browned.
03 - Add the minced garlic and cook for 1 minute until fragrant.
04 - Stir in the butter beans, thyme, salt, and pepper.
05 - Pour in the vegetable broth. Bring to a gentle simmer.
06 - Cover and cook for 10 minutes, stirring occasionally, until everything is heated through and flavors meld.
07 - Uncover, add the lemon zest, and simmer another 2–3 minutes to thicken slightly.
08 - Taste and adjust seasoning if needed.
09 - Sprinkle with fresh parsley before serving.