Greek Bean Soup with Carrots and Celery (Fasolada)

500 gr (17 oz) navy or cannellini beans.

1 large onion coarsely chopped.

3 carrots coarsely sliced.

2 celery sticks sliced.

2-3 large sweet and ripe tomatoes.

2 teaspoons of concentrated tomato paste.

½ cup of extra virgin olive oil.

Salt and ground pepper.