I made this soup today and it was the easiest tasty soup I've ever made. It's a crock pot dish but you could do it stove top pretty easy, too.
2 Tbs olive oil
3 garlic cloves, minced
1 1/2 pounds Yukon Gold potatoes, peeled and diced
6 cups vegetable stock
enough pesto to put dollops in your bowl
1/4 toasted pine nuts (optional)
Set your cooker to high and add oil and garlic. Peel and chop the potatoes while the garlic softens up. When the garlic smells nice, add your potatoes and broth and set the crock pot to low for 6 to 8 hours. When you're ready to eat, puree the potatoes with an immersion blender or run it in batches through a regular blender or food processor until smooth (it shouldn't take long).
After you pour your soup into bowls, swirl in a spoonful of pesto and sprinkle some pine nuts on it.
Notes: your broth is a major flavor here, so pick a good one that you really like. You can make your own pesto, of course, but I just used a pre-made one that I like.