Heat 3 tablespoons of the olive oil in a large soup pot and saute the onions and chopped chili pepper over medium-low heat, stirring with a wooden spoon, until the onions begin to caramelize for 10-12 minutes. Add the celery and carrots and continue to cook for another 10 to 15 minutes, stirring occasionally.

Add the beans to the pot, toss to coat, and pour in the water and the bay leaf. Bring to a boil over high heat, reduce flame and simmer, partially covered, for 15 minutes, until the beans are completely soft.

Add the tomatoes. Ten minutes before removing from heat, add the parsley and season with salt and pepper. When the beans are done, pour in the remaining olive oil and lemon juice or vinegar. Serve hot.