Rinse the butter beans under cold water if using canned. Trim and slice the leeks, and mince the garlic.

In a large pot, heat the olive oil over medium heat. Add the sliced leeks and sauté for about 5 minutes until softened. Add the minced garlic and cook for an additional 1-2 minutes until fragrant.

Add the butter beans and vegetable broth to the pot. Stir to combine, and season with salt and black pepper.

Bring the mixture to a gentle simmer. Cover and cook for about 20 minutes, allowing the flavors to meld.

Remove from heat, garnish with chopped parsley, and serve warm as a side or light main dish.