Step 1

Heat the oil in a large stockpot or dutch oven over medium heat.

Step 2

Add the leeks, and cook, stirring occasionally, until the leeks begin to soften, about 10 minutes. Next, add the garlic, potatoes, thyme, salt and pepper, and cook for about 5 minutes.

Step 3

Add the vegetable broth and bay leaves, and bring to a boil. Reduce the heat to low, and simmer for 30 to 40 minutes, or until the vegetables are tender.

Step 4

Use an immersion blender to blend until smooth and consistent without any vegetable chunks. Fold in the sour cream and adjust seasoning to your taste.

Step 5

Serve with fresh watercress and toast, if desired