Make the fish paste: Place the White fish fillets in a food processor with 1–2 tablespoons of Thai red curry paste, the Egg, 1–2 teaspoons of Fish sauce, a teaspoon of grated Palm sugar (or to taste) and a pinch of Salt. Pulse until you have a smooth, sticky paste.
Bind and flavor: Transfer the paste to a bowl and stir in 1–2 tablespoons of Rice flour to help it hold together. Fold in finely chopped Yardlong beans and thinly shredded Kaffir lime leaves for texture and fragrance. Chill the mixture for 15 minutes to firm up slightly.
Shape the cakes: Wet your hands and form the mixture into small, flattened patties (about 2–3 inches across). Keep a tray nearby and continue until all the mixture is used.
Fry the fish cakes: Heat a few tablespoons of neutral oil in a skillet over medium-high heat. Fry the cakes in batches, pressing gently to flatten, until golden brown and cooked through — about 3–4 minutes per side. Drain on paper towels.
Prepare the dipping sauce: In a small saucepan or bowl, combine 3 tablespoons of Rice vinegar, 3 tablespoons of Water, 2 tablespoons of Sugar and 1–2 tablespoons of Fish sauce. Add thinly sliced Shallots and thinly sliced Thai bird's eye chilies to taste. Warm just enough to dissolve the sugar, then let the sauce cool so the flavors meld.
Quick cucumber salad: Thinly slice the Cucumber and toss with a little of the prepared dipping sauce (or a splash of Rice vinegar, a pinch of Sugar and Salt) and the remaining sliced Shallots. This cool, crisp salad balances the richness of the cakes.
Finish and garnish: Transfer the fish cakes to a serving plate, sprinkle with coarsely crushed Peanuts and chopped Cilantro. Serve immediately with the dipping sauce and cucumber salad on the side.
Tips: If the mixture feels too wet, add a little more Rice flour or chill longer. Adjust the heat of the sauce with more or fewer Thai bird's eye chilies.
