Slow-Roasted Barramundi with Lemon Myrtle Butter

By AislePrompt Test Kitchen · Reviewed by AislePrompt Editorial · ·

Delicate barramundi fillets slow-roasted and topped with a fragrant lemon myrtle-infused butter for a subtle citrus aroma. This australian-inspired seafood (gluten free) ready in about 35 minutes pairs 6 oz each barramundi fillets, softened unsalted butter, lemon myrtle powder for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 280 calories and feeds 4, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

Prep: 10 min Cook: 25 min Serves 4 Australian cuisine 280 cal/serving
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Ingredients

Instructions

  1. Step 1: Preheat the oven to 275°F (135°C). In a small bowl, mix 4 tbsp softened unsalted butter with 1 tsp lemon myrtle powder, 1 tsp sea salt, and 1/2 tsp black pepper until well combined.
  2. Step 2: Pat dry 4 barramundi fillets and place them on a lightly oiled baking tray; drizzle 2 tbsp olive oil and 1 tbsp fresh lemon juice evenly over the fillets.
  3. Step 3: Spread the lemon myrtle butter evenly over the top of each fillet.
  4. Step 4: Roast the barramundi in the preheated oven for 20-25 minutes until the fish flakes easily with a fork and has a translucent, moist texture.
  5. Step 5: Remove from oven and garnish with 2 tbsp chopped fresh parsley before serving for a fresh herbal note.

Equipment for this recipe

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Frequently asked questions

How long does Slow-Roasted Barramundi with Lemon Myrtle Butter take to make?

Total time is about 35 minutes (10 min prep + 25 min cook). Most home cooks find this fits comfortably into a weeknight; double the batch on Sunday for two dinners.

How do I store leftover Slow-Roasted Barramundi with Lemon Myrtle Butter?

Cool to room temperature within 2 hours, then store in an airtight container in the fridge for up to 4 days. Reheat covered in a 350°F oven for 10-12 minutes, or microwave at 70% power in 60-second bursts to keep 6 oz each barramundi fillets from drying out.

Can I substitute ingredients in Slow-Roasted Barramundi with Lemon Myrtle Butter?

Yes — most ingredients in this recipe have flexible swaps. For oil, use any neutral high-smoke-point oil (avocado, grapeseed, refined coconut). For aromatics, dried herbs at ⅓ the volume of fresh work in a pinch. The full ingredient list is shoppable on Instacart so you can see substitutes in real time.

How do I scale Slow-Roasted Barramundi with Lemon Myrtle Butter for a different number of people?

The recipe is written for 4 servings. Multiply each ingredient by (your serving target / 4). Cook time stays roughly the same up to 2x; for 3-4x batches, switch from a skillet to a sheet pan or stockpot so the food isn't crowded — overcrowding steams instead of browns.

Is Slow-Roasted Barramundi with Lemon Myrtle Butter gluten free?

Yes — this recipe is tagged gluten free based on its ingredient list. Always cross-check labels for packaged ingredients (sauces, broths, condiments) since formulations vary by brand.

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