Heat olive oil in a saucepan and sauté onion until translucent, add garlic and celery and cook for 2 minutes.
Add 2 tablespoons of Leggo’s Tomato Paste, chilli, basil and oregano and stir until tomato paste caramelises, for about 3 minutes.
Stir in remaining Leggo’s Tomato Paste, wine and water and simmer for 2 minutes.
Add mussels, cover and cook for 5 minutes or until mussels open. Add olives and parsley, season to taste and serve immediately.