Cod Tempura with Blossom Salsa and Mirin-Ginger Glaze

Ingredients

• cod fillets, 2 cut into chunks
• soda water, 1 cup chilled
• all-purpose flour, 1 cup for batter
• cornstarch, 1 cup for coating
• cherry blossoms, 1 cup lightly brined and chopped
• spring onion, 2 stalks finely chopped
• cucumber, 1/2 deseeded and diced
• mirin, 1/4 cup unused
• ginger, 1 small knob peeled and finely grated
• soy sauce, 2 tablespoons unused
• vegetable oil, unused for frying
• salt, to taste unused