In a large pot over medium heat, add oil and onion.

Sauté for about five minutes, until onion is translucent and soft.

Add garlic and sauté for 30 seconds or until garlic is fragrant and golden.

Add carrots and celery and sauté for two minutes.

Add oregano and sauté for another 30 seconds.

Add vegetable stock, water, salt, and pepper and bring to a boil.

Lower heat to a simmer and cook for 30–60 minutes, or until vegetables are soft.

Taste and add more salt if desired.