Flip out a winner tonight with Hayden Quinn’s okonomiyaki with prawns

Name: Flip out a winner tonight with Hayden Quinn’s okonomiyaki with prawns
Cuisine: Japanese
Ingredients: 1 1/2 cups (225g) plain flour; 1 tsp baking powder; 4 eggs, lightly beaten; 2 tbs white (shiro) miso paste; 1 cup (250ml) cold soda water; 1/4 white cabbage, finely shredded; 1 zucchini, coarsely grated; 3 long green shallots, thinly sliced, plus extra, thinly sliced, to serve; 20 medium green prawns, peeled, deveined, halved horizontally; 1/3 cup (80ml) sunflower oil; Avocado wedges, Kewpie mayonnaise, baby spinach and toasted white sesame seeds, to serve