Heat oil in a large pot over medium heat
Add chopped onion, garlic, carrots, and celery
Cook until the vegetables begin to soften
Add diced potatoes and any other desired vegetables
Pour in vegetable broth or water
Add salt, pepper, and herbs such as thyme or bay leaf
Bring to a boil
Reduce heat and simmer until vegetables are tender
Stir in leafy greens or peas near the end
Taste and adjust seasoning
Serve hot