Salt cod soup (Zuppa di baccala)

Ingredients

• 2/3 pound salt cod
• 1 1/3 pounds fresh cod
• 2/3 pound salt cod
• 1 white onion peeled
• 2 carrots small, peeled
• 2 sticks celery trimmed, pale green inner leaves reserved
• 2 cloves garlic peeled
• 1 bunch fresh flat leaf parsley stalks and leaves separated
• extra virgin olive oil
• 1 red chilli small dried, crumbled
• 2 1/4 cups plum tomatoes good-quality tinned
• 1 3/4 cups chicken stock light organic
• sea salt
• ground black pepper freshly
• 1 lemon