Shrimp Tempura Udon Noodle Soup (Ebiten Udon)

Name: Shrimp Tempura Udon Noodle Soup (Ebiten Udon)
Prep time: 30 min
Cook time: 15 min
Total time: 45 min
Cuisine: Japanese
Ingredients: 100ml cold water chilled; 50ml sparkling water chilled; 15g potato starch + 75g weak flour sifted, mixed and refrigerated for 30 mins; Flour for dusting; 1/2 tbsp of Japanese egg mayonnaise OR 1/2 a whisked egg; 8 Tiger Prawns (or similar large prawns); Oil for deep frying (vegetable, canola, peanut or white sesame); 1 litre (4 cups) dashi (I recommend kombu & bonito dashi / kombu & shiitake dashi); 5 tbsp (75ml) soy sauce; 2 tbsp (30ml) mirin; 1/2 tsp salt; 4 portions of udon noodles; Spring onion finely sliced to garnish; 8-12 slices kamaboko (optional); Shichimi Japanese 7 spice powder (optional)