Preheat oven to 190°C and grease 3 12-cup mini muffin tins. Sift cornmeal, flour, sugar, baking powder, and celery salt into a bowl.
Stir in chives and coriander. In a separate bowl, whisk buttermilk, egg and oil. Add buttermilk mixture to dry ingredients, stirring just until incorporated (do not overmix).
Quickly stir in corn. Divide batter equally among prepared muffin cups. Bake muffins until tester inserted into center comes out clean, about 8 minutes. Cool for 10 minutes, then turn out to cool completely.
For the Baby Prawn Salad
Preheat gas grill to high heat. Grill corn until charred lightly on all sides and kernels are bright yellow. Let cool and remove kernels into a bowl.
Toss all ingredients together and season to taste. The creaminess of the avocado will bind the salad together.
To serve, cut the top of each muffin and spoon a little shrimp salad in each. Cap with muffin top (optional) and serve.