Heat the olive oil in a large cast iron skillet over medium heat. Add the onion, garlic, carrots, celery, and bell pepper. Cook, stirring occasionally, until the vegetables are softened, about 5 minutes.
Add the white beans, vegetable stock, oregano, thyme, salt, and pepper. Bring to a simmer and cook for 15 minutes.
Stir in the lemon juice. Taste and adjust the seasoning, if needed. Serve hot.