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

This panko-crusted rainbow trout is a showstopper, featuring a crispy golden crust and tender, flaky fish. It’s served alongside velvety roasted garlic mashed potatoes and perfectly roasted green beans, all brought together with a tangy creamy mustard sauce. The combination of textures and flavors—crunchy, creamy, savory, and bright—makes this dish feel like a special occasion meal, yet it’s surprisingly simple to prepare.

The secret lies in roasting the garlic until sweet and mellow, then mashing it into the potatoes for an aromatic depth. The trout gets a generous coating of panko and Parmesan, which turns beautifully crisp in the oven. A quick mustard sauce adds a luscious finish, tying everything together. Whether you’re cooking for a weeknight dinner or a festive gathering, this recipe is sure to impress.

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Ingredients

0.5 cup Panko BreadcrumbsView ingredient guideLike ingredientDislike ingredient

12 ounce PotatoesView ingredient guideLike ingredientDislike ingredient

ounce Green BeansView ingredient guideLike ingredientDislike ingredient

6 ounce AsparagusView 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

1 teaspoon (tsp) SugarView ingredient guideLike ingredientDislike ingredient

3 teaspoon (tsp) Cooking OilView ingredient guideLike ingredientDislike ingredient

2 tablespoon (tbsp) ButterView ingredient guideLike ingredientDislike ingredient

teaspoon (tsp) SaltView ingredient guideLike ingredientDislike ingredient

teaspoon (tsp) Black PepperView ingredient guideLike ingredientDislike ingredient

Instructions

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

Can I make this recipe gluten-free?

Use gluten-free panko breadcrumbs and ensure all other ingredients are gluten-free. The rest of the recipe remains the same.

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.