Heat the oil in a 3-quart pot over medium-high heat; add the onion, celery, carrot, and bell pepper and cook until starting to soften, about 3 to 5 minutes.
Turn the heat down to medium, stir in the tomato paste, garlic and thyme, and cook 2 minutes; stir in the flour and cook 2 minutes more. Add the stock, tomato, bay leaf, oregano, salt, pepper, and beans, (Mash a 1/2 can of the beans before adding to make a thicker soup.) and bring to a boil; turn the heat down and simmer 15 minutes (uncovered).
Turn the heat off and stir in the cream and parsley.