Gochujang Butter Meets Volcanic Trout
Korean home cooks finish firm fish with a short, high-heat sear and a sugar-salt-chilli glaze so the skin crisps while the flesh stays moist. Lake Taupō rainbow trout suits this approach: its oil content carries the fermented heat of gochujang and the nuttiness of toasted sesame without drying out under a hot pan. The sauce uses pantry staples common in Seoul kitchens and takes under ten minutes once the fillets are ready.
Ingredient List
Prep time: 15 minutes | Cook time: 12 minutes | Serves: 4
The Fish
- 4 Rainbow Trout Fillets: Skin on, pin bones removed, about 180g each, from Lake Taupō
- 1 Teaspoon Fine Sea Salt
- 1/2 Teaspoon Freshly Ground Black Pepper
- 1 Tablespoon Neutral Oil: Rice bran or grapeseed, for searing
The Gochujang Butter Glaze
- 40g Unsalted Butter
- 2 Tablespoons Gochujang: Korean red chilli paste; use a standard supermarket brand
- 1 Tablespoon Soy Sauce
- 1 Tablespoon Mirin
- 1 Tablespoon Honey
- 2 Cloves Garlic: Finely grated
- 1 Teaspoon Fresh Ginger: Finely grated
- 1 Teaspoon Toasted Sesame Oil
- 1 Tablespoon Rice Vinegar
The Garnish and Sides
- 2 Spring Onions: Thinly sliced on the diagonal
- 1 Tablespoon Toasted White Sesame Seeds
- 1 Red Chilli: Thinly sliced (optional)
- Steamed Short-Grain Rice: For serving
- Quick Cucumber Banchan: 1 Lebanese cucumber, sliced; 1 teaspoon salt; 1 teaspoon sugar; 1 teaspoon rice vinegar
Preparation and Cooking Method
1. Season and Dry the Fillets
Pat the trout fillets completely dry with paper towels on both sides. Moisture on the skin prevents browning. Season the flesh side only with sea salt and black pepper. Leave the fillets skin-side up on a plate for 5 minutes while you mix the glaze so surface moisture evaporates further.
2. Mix the Glaze
In a small saucepan over low heat, melt the butter. Whisk in gochujang, soy sauce, mirin, honey, grated garlic, and grated ginger until smooth. Simmer for 2 minutes, stirring, until the mixture thickens slightly and smells fragrant. Remove from heat. Stir in toasted sesame oil and rice vinegar. Set aside; the glaze will thicken a little as it cools.
3. Prep the Cucumber Banchan
Toss cucumber slices with 1 teaspoon salt in a bowl. Rest 5 minutes. Squeeze out liquid, then toss with sugar and rice vinegar. Keep cold until plating.
4. Sear the Trout
Heat a large heavy skillet (cast iron or stainless steel) over medium-high heat for 2 minutes. Add the neutral oil and swirl. Place fillets skin-side down. Press each fillet gently with a spatula for the first 15 seconds so the skin stays flat. Cook undisturbed for 3 to 4 minutes. The skin should turn deep gold and release cleanly from the pan when ready. Flip and cook the flesh side for 1 to 2 minutes only. Internal temperature at the thickest point should read 52 to 54°C for medium; residual heat will finish the cook.
5. Glaze in the Pan
Reduce heat to low. Spoon half the gochujang butter over the fillets. Tilt the pan and baste for 30 to 45 seconds so the glaze coats the flesh and edges of the skin. Remove fillets to a warm plate. Pour any remaining pan juices back into the glaze saucepan and warm through for 20 seconds.
6. Plate and Finish
Spoon steamed rice onto four plates. Set one fillet on each portion, skin-side up so it stays crisp. Drizzle the remaining glaze over the fish. Scatter spring onion, toasted sesame seeds, and optional chilli. Serve the cucumber banchan on the side.
Chef’s Notes for Success
- Skin crispness: Dry skin and a hot pan are non-negotiable. If the skin sticks, cook 30 seconds longer before attempting to flip.
- Gochujang heat: Standard gochujang sits in the mild-medium range. For less heat, cut the paste to 1 tablespoon and add 1 extra teaspoon honey.
- Fillet thickness: Fillets thicker than 3cm at the head end need 1 extra minute skin-side down. Thin tail pieces cook in 2 to 3 minutes total.
- Butter separation: If the glaze looks split after cooling, whisk in 1 teaspoon warm water over low heat to re-emulsify.
- Make-ahead: Glaze keeps 4 days in a sealed jar in the fridge. Rewarm gently before basting; do not boil or the honey will scorch.
- Whole fish option: Two 600g whole trout, scored and roasted at 200°C for 18 to 20 minutes, can replace fillets. Brush glaze on for the final 5 minutes under the grill.
Why This Pairing Works
Gochujang brings fermented chilli, glutinous rice, and soybean depth. Honey and mirin supply surface sugars that caramelise in the final baste. Rice vinegar brightens the finish so the sauce does not taste flat against the trout’s natural oil. Lake Taupō fish feed in cold volcanic water and carry a clean mineral note; the glaze accents that flavour instead of covering it. Short-grain rice absorbs leftover sauce. The salted cucumber cuts fat between bites.
Serve immediately after glazing. Leftover flesh flakes well into rice bowls the next day with a squeeze of fresh lime and extra spring onion.
Fish the Lake, Cook the Catch
Our morning charters on Lake Taupō put you on rainbow trout while the water is still quiet. Guides work the drop-offs and river mouths where fish of 400 to 600g are common; that size fillets cleanly for this recipe. We can fillet on board, pack whole fish on ice, or both. Rods, tackle, and cleaning stations are included.
Book at greatlakefishingtours.club. Bring a cooler so your catch reaches the kitchen in condition worth of a hot pan and a proper glaze.