Steps
1. Marinate fish fillets with liquid salt koji, white pepper powder, and white wine. Cover and refrigerate for at least 30 minutes.
2. Peel and cube the potato, boil in salted water until tender (about 15 minutes). Drain and mash until smooth.
3. Mix mashed potato with avocado oil, a pinch of black pepper, and 1/4 tsp salt. Keep warm.
4. Prepare the batter: sift together low-gluten flour and potato starch.
5. Slowly whisk in chilled apple tea shandy and 1 tsp avocado oil until smooth and thick but pourable.
6. Lightly coat marinated fish fillets with potato starch then dip into the batter. Sprinkle paprika evenly over the batter surface.
7. Preheat oven to 200°C (390°F) and place the battered fish fillets on a lined baking tray.
8. Bake for 12-15 minutes until the batter is puffed and golden.
9. Remove from oven and lightly brush fish with avocado oil for shine.
10. Serve fish fillet atop a bed of silky mashed potato. Enjoy immediately while warm.