Really good Fish Cakes

Bahan-bahan (4 porsi)

• 500 g / 1 lb white fish fillets (, skinless boneless, cut into 3cm / 1.2" pieces (Note 1))
• 60 g / 4 tbsp unsalted butter
• 1/2 tsp salt
• 1/4 tsp black pepper
• 800 g / 1.6 lb potatoes ( – Sebago (Aus), Russet (US), Maris Piper / King Edwards (UK) (Note 2) (makes 500g flesh))
• 2 g arlic cloves (, finely minced)
• 1/2 cup green onion (, finely sliced (~1 large stem))
• 2 large red chillis (, deseeded and finely chopped (can omit))
• 1 tbsp thyme leaves (, chopped)
• 1 tbsp parsley (, finely chopped)
• 3/4 tsp salt
• 1 cup flour
• 2 eggs (, lightly whisked)
• 1 1/4 cups panko breadcrumbs ((sub ordinary breadcrumbs))
• 1 cup vegetable or canola oil (, for frying (~ 1cm / 0.4" depth))