In a large pot over medium-high heat, heat the olive oil. Add the onion and garlic and sauté for 5 minutes, stirring occasionally, until the onion is softened and lightly browned.
Add the salt, pepper, oregano, and basil and stir to combine. Cook for 1 minute.
Add the vegetable broth, tomatoes, black beans, red beans, and white beans. Decrease the heat to low and simmer for 15 minutes, stirring occasionally.