Melt the butter in a large stockpot over medium-high heat. Add the leeks and sauté for 5 minutes, stirring occasionally. Add the garlic and a generous pinch of salt and pepper and sauté for 1 minute, stirring frequently.
Add the vegetable broth, potatoes, bay leaves and stir to combine. Continue cooking until the broth reaches a simmer. Reduce heat to medium-low (or whatever temperature is needed to maintain a low simmer). Cover and simmer for 15 minutes or until the potatoes are fork-tender.
Remove and discard the bay leaves. Use an immersion blender to purée about half of the soup, which will help to make the broth nice and thick.
Add the cream, cheddar and kale and stir to combine. Continue cooking for 3-4 minutes or until the kale has wilted.
Taste and season with salt and pepper as needed.
Serve. Serve warm, garnished with lots of scallions (plus extra cheddar and black pepper, if you would like), and enjoy!
