If using fresh corn, wash and shuck ears and cut corn from cob. Heat oil over medium heat in cast iron skillet or large pan and add corn, cooking until brown (about 5 minutes).
Slice potatoes, onion and garlic and add to skillet with corn, cooking until vegetables begin to soften and become brown, about 7 minutes.
Transfer vegetable mixture to large soup pot and add vegetable broth and bring to a boil.
Reduce heat and simmer for about thirty minutes. Add salt and pepper to taste.
Remove soup from heat and blend until smooth with immersion blender. Add additional spices, if needed, and top with chili oil before serving.
The soup may need more or less vegetable broth, depending on your personal consistency preference. If you prefer a thicker soup then add only 3/4 of broth and add more if needed to desired consistency.