Golden Panko-Crusted Rainbow Trout with Garlic Mashed Potatoes and Creamy Mustard Sauce

This golden panko-crusted rainbow trout is a restaurant-quality dish you can easily make at home. The fish is coated in a crispy panko and Parmesan crust, then baked to perfection alongside roasted garlic and green beans. The creamy mustard sauce adds a tangy richness that ties everything together.

Paired with velvety roasted garlic mashed potatoes, this meal is both comforting and impressive. The roasted garlic infuses the potatoes with deep, aromatic flavor, while the green beans provide a fresh, crisp contrast. It’s a complete dinner that will make any weeknight feel special.

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Ingredients

0.5 cup Panko BreadcrumbsView ingredient guideLike ingredientDislike ingredient

12 ounce PotatoesView ingredient guideLike ingredientDislike ingredient

8 ounce Green BeansView ingredient guideLike ingredientDislike ingredient

4 ounce Cream Sauce BaseView ingredient guideLike ingredientDislike ingredient

5 teaspoon White Wine VinegarView ingredient guideLike ingredientDislike ingredient

2 clove GarlicView ingredient guideLike ingredientDislike ingredient

3 tablespoon Parmesan CheeseView ingredient guideLike ingredientDislike ingredient

10 ounce Rainbow TroutView ingredient guideLike ingredientDislike ingredient

4 teaspoon Dijon MustardView ingredient guideLike ingredientDislike ingredient

teaspoon (tsp) SaltView ingredient guideLike ingredientDislike ingredient

1 teaspoon (tsp) SugarView ingredient guideLike ingredientDislike ingredient

1 tablespoon (tbsp) Cooking OilView ingredient guideLike ingredientDislike ingredient

2 tablespoon (tbsp) ButterView ingredient guideLike ingredientDislike ingredient

teaspoon (tsp) Black PepperView ingredient guideLike ingredientDislike ingredient

Instructions

1. Preheat the oven to 450°F with a rack in the middle position (and top position if making 4 servings). Peel the garlic cloves. Peel and dice the potatoes into ½-inch pieces. Trim the green beans if needed. Place the garlic cloves in the center of a small piece of foil, drizzle with oil and season with salt and pepper. Fold the foil into a packet and place it on a baking sheet. Roast on the middle rack for 10 minutes (more items will be added to the sheet later).
2. Meanwhile, put the diced potatoes in a medium pot and add enough salted water to cover by 2 inches. Bring to a boil and cook until tender, 15-20 minutes. Reserve ½ cup of the potato cooking water (¾ cup for 4 servings), then drain. Return the potatoes to the pot and cover to keep warm. While the potatoes cook, combine the panko, half the Parmesan, 1 tablespoon oil (2 tablespoons for 4 servings), salt and pepper in a medium bowl.
3. Pat the rainbow trout dry with paper towels and season all over with salt and pepper. Place the fish on a plate, drizzle the skin sides with oil and rub to coat. Arrange the fish skin side down on the plate. Spread a thin layer of half the Dijon mustard over the tops of the fish. Mound the panko mixture on top, pressing firmly to adhere. After the garlic has roasted for 10 minutes, remove the baking sheet from the oven. Carefully add the trout to one side of the sheet (keep the garlic packet on the sheet).
4. Toss the green beans on the empty side of the sheet with a drizzle of oil, salt and pepper. Return the sheet to the middle rack and roast until the vegetables are tender and the trout is browned and cooked through, 10-12 minutes. (For 4 servings, toss the green beans on a second baking sheet; roast the green beans on the middle rack and the trout and garlic on the top rack.)
5. In a small bowl, combine half the white wine vinegar, half the cream sauce base, the remaining Dijon mustard and 1 teaspoon sugar (all the vinegar and 2 teaspoons sugar for 4 servings). Heat a small pan over medium heat. Add the cream sauce mixture and cook, stirring occasionally, until thickened, 2-4 minutes. Remove from heat and stir in 1 tablespoon butter (2 tablespoons for 4 servings). Season with salt and pepper. Cover and keep warm.
6. Add the roasted garlic (with its oil), the remaining cream sauce base, the remaining Parmesan and 1 tablespoon butter (2 tablespoons for 4 servings) to the pot with the potatoes. Mash with a potato masher until smooth and creamy, adding splashes of the reserved potato cooking water as needed. Season with salt and pepper.
7. Divide the trout, green beans and mashed potatoes among plates. Drizzle the trout with the creamy mustard sauce and serve. Tip: If the sauce has thickened too much, add a splash of water and stir to thin.

Recipe Tips

FAQ

Can I use a different type of fish?

Yes, you can substitute rainbow trout with other firm white fish like cod or tilapia. Adjust cooking time as needed.

How do I store leftovers?

Store leftovers in an airtight container in the refrigerator for up to 2 days. Reheat gently in the oven or microwave.

Can I make this dish dairy-free?

To make it dairy-free, use dairy-free butter and omit the Parmesan cheese. The cream sauce base may contain dairy, so check the label or substitute with a dairy-free cream alternative.