Dice onions, carrots, celery, potatoes, and tomatoes.
Heat olive oil in a pot and sauté onions, celery, and carrots.
Add potatoes and tomatoes, and continue to sauté.
Pour in vegetable broth or water.
Add bay leaves and herbs (such as thyme).
Bring to a simmer over medium-low heat until the vegetables are tender.
Season with salt and pepper.