Heat olive oil in a pot over medium-low heat.

Add sliced leeks and chopped onion to the pot and saute for 10 minutes, or until soft and fragrant, stirring occasionally.

In a large pot, bring chicken or vegetable broth to a boil.

Add the sauteed leeks and onion to the boiling broth.

Add minced garlic, cubed red potatoes, dried thyme, and chili powder to the pot.

Cover the pot and reduce heat to low.

Simmer for 20-30 minutes, or until potatoes are very soft and fall apart when forked.

Remove the pot from heat and let it cool slightly.

Using a blender or immersion blender, puree the soup until smooth. Be cautious and blend in batches, filling the blender no more than halfway.

Pour the pureed soup back into the pot.

Reheat the soup over low heat until warmed through.

Season to taste with salt and pepper.