Drain can of salmon. Add water to juice to make 600ml / 1pint. Mash fish, cheese, tomatoes, pesto in a bowl. Mix flour, salt, eggs, basil to form firm dough. Turn onto a floured surface. Knead for 1 minute. Break into lemon size pieces, knead thoroughly. Roll into 2mm sheets. Cut dough into 3.5cm / 1.2 inch circles. Put small amount of salmon filling into center of each circle. Fold in half and press edges firmly together Dry on each side floured board for 1 hour. Put fish stock, onion and garlic in a pan. Bring to boil then simmer. Drop one third of ravioli into stock. Cook for 10 minutes. Remove and keep warm. Cook remainder in same way. Blend remaining ingredients. Heat until boiling then simmer for 5 minutes. Serve ravioli with sauce and a salad. Serves 6. Approx. 300 kcals per serving