Heat olive oil in a heavy large saucepan over medium heat.

Add chopped onion and sauté until golden, about 10 minutes.

Add chicken broth, potatoes, garlic, and bay leaf; bring to a boil.

Reduce heat to medium-low; cover and simmer until potatoes are very tender, about 20 minutes.

Cool slightly.

Discard bay leaf.

Coarsely puree soup in a blender one cup at a time, about 20 seconds per batch (do not overprocess).

Return the pureed soup to the same saucepan.

Season to taste with salt and pepper.

Simmer until heated through.

Ladle soup into bowls.

Sprinkle with chives and thyme and serve.