Wash and chop the leeks and potatoes.

Chop the onion, mince the garlic, and chop the spring onions (reserve some for garnish).

Heat the ghee in a large pot over medium heat.

Add the onions, leeks, and salt. Sauté until softened (about 5 minutes).

Add the garlic and toss gently for 30 seconds.

Add the potatoes, bay leaf, and chicken stock. Bring to a rolling boil.

Reduce heat and simmer until the vegetables are softened (30-45 minutes).

Remove half of the soup and set aside.

Puree the remaining half of the soup using a blender or immersion blender.

Pour the chunky soup back into the pureed soup and stir.

Crumble the stilton cheese.

Divide the stilton among 6 serving bowls.

Ladle the soup into the bowls.

Top each bowl with a spoonful of sour cream and chopped spring onions.

Add a lemon twist (optional) and season with salt and pepper to taste.

Serve with buttered toast.