Heat medium soup pot over medium-high heat. Add the olive oil and sausage and brown. Add veggies, bay leaf and beans. Season with salt and pepper. Cook mixture 5 minutes to begin to soften the vegetables. Add rabe and wilt. Add stock and cover pot. Raise heat and bring soup to a boil. Reduce heat to simmer and cook 15 minutes. Adjust seasonings and serve soup with grated cheese, for topping.