Dinner

Salmon & Asparagus One-Pot Gratin Recipe

BySophie Carsel November 20, 2025November 20, 2025

Introduction

This Salmon & Asparagus One-Pot Gratin is an elegant yet easy dish perfect for a weeknight dinner or special occasion. Creamy, cheesy, and topped with a crunchy breadcrumb crust, it combines tender salmon and fresh asparagus in one comforting casserole.

A white pan with two handles holds a creamy baked dish featuring four large salmon pieces arranged unevenly in a single layer, topped with a golden-brown breadcrumb crust with green herb flecks. Bright green asparagus spears are scattered on top and partially buried in the creamy white sauce with a slightly browned surface around the edges. The pan sits on a light green placemat over a white marbled surface, with a clear glass of sparkling water nearby and a white spoon with yellow speckles resting beside it. photo taken with an iphone --ar 4:5 --v 7

Ingredients

30g dried breadcrumbs
2 sprigs parsley, leaves picked and chopped
100g parmesan
1 tsp olive oil
25g unsalted butter
1 red onion, finely chopped
1 garlic clove, crushed or finely grated
300ml double cream
100ml milk
500g asparagus, trimmed and halved
4 skinless salmon fillets

Instructions

Step 1: Preheat the oven to 200°C (180°C fan) or gas mark 6. In a small bowl, combine the dried breadcrumbs, chopped parsley, and 25g parmesan. Set this mixture aside.
Step 2: Heat the olive oil and butter in a large flameproof casserole dish over medium heat. Add the finely chopped red onion and cook for about 5 minutes until it starts to soften.
Step 3: Stir in the crushed garlic and cook for another 1-2 minutes until fragrant and slightly softened.
Step 4: Pour in the double cream and milk, then add the remaining parmesan. Bring the mixture to a gentle simmer, stirring until the cheese has melted completely. Season well with salt and pepper, then remove the casserole from the heat.
Step 5: Add the trimmed and halved asparagus to the creamy sauce, ensuring it is fully submerged.
Step 6: Nestle the skinless salmon fillets into the sauce, placing them skin-side down.
Step 7: Evenly scatter the cheesy breadcrumb mixture over the salmon fillets.
Step 8: Transfer the casserole to the preheated oven and bake for 14-16 minutes until the salmon is cooked through and the breadcrumb topping is lightly golden and crisp.

Tips & Variations

Use fresh breadcrumbs for a lighter, crunchier topping if preferred.
Swap parsley for fresh dill or chives to complement the salmon’s flavor.
For extra richness, add a tablespoon of Dijon mustard to the cream sauce.
If asparagus is out of season, try tender green beans or broccoli florets as a substitute.

Storage

Store any leftovers in an airtight container in the refrigerator for up to 2 days. Reheat gently in the oven at 160°C until warmed through to preserve the crispy topping. Avoid microwaving to keep the gratin texture intact.

How to Serve

The image shows a white round pan filled with a creamy dish featuring four lightly browned salmon fillets partially covered by a golden breadcrumb topping. Bright green asparagus spears are scattered between the fillets, adding color contrast. The creamy sauce under the topping is pale with a slightly thick texture, pooling around the salmon and asparagus. The pan is placed on a light green cloth with a textured green surface beneath it. Next to the pan, there is a white spoon with yellow speckles and a glass of sparkling water is visible above. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use frozen salmon or asparagus for this recipe?

Yes, you can use frozen salmon and asparagus. Thaw them fully and pat dry before cooking to avoid excess moisture in the gratin.

Can I prepare this dish ahead of time?

You can assemble the gratin up to the baking step, cover it, and refrigerate for a few hours. Bake it just before serving, adding a few extra minutes to the cooking time if it’s cold from the fridge.