Dinner

Salmon with Mustardy Celeriac Mash Recipe

ByEthan Lark January 17, 2026January 17, 2026

Introduction

This Salmon with Mustardy Celeriac Mash is a light and flavorful dish perfect for a wholesome dinner. The creamy celeriac mash pairs beautifully with the tangy mustard dressing and tender grilled salmon, making it both nutritious and satisfying.

A white plate with a base layer of mashed cauliflower mixed with quinoa and wilted spinach, showing a creamy texture with bits of green spinach leaves scattered throughout. On top of this base layer rests a thick, cooked salmon fillet with a light golden-brown crust and some black pepper sprinkled on it. The dish is placed on a white marbled surface with sunlight casting soft shadows, and a fork and knife lie beside the plate. photo taken with an iphone --ar 4:5 --v 7

Ingredients

2 salmon fillets, about 100g/4oz each
700g celeriac, peeled and cut into chunks
2 tsp wholegrain mustard
2 tsp lemon juice
100g baby spinach leaves
Olive oil (for brushing and dressing)
Salt and pepper
Pinch of sugar

Instructions

Step 1: Preheat your grill to medium. Brush the salmon fillets lightly with olive oil and season well with salt and pepper. Line a grill pan with foil and place the salmon on top.
Step 2: Place the celeriac chunks in a pan and cover with cold salted water. Bring to a boil, then reduce the heat, cover, and simmer for 12-15 minutes until the celeriac is tender.
Step 3: While the celeriac cooks, whisk together the wholegrain mustard, lemon juice, a pinch of sugar, salt, pepper, and 1 tablespoon of olive oil to create the mustard dressing.
Step 4: Grill the salmon for about five minutes on each side until cooked through and flaky.
Step 5: Drain the cooked celeriac, reserving 1 tablespoon of the cooking water. Return the celeriac to the pan and mash it until fairly smooth.
Step 6: Add the baby spinach leaves to the mash and stir occasionally over low heat until the spinach is wilted.
Step 7: Stir in 1 tablespoon of the mustard dressing along with the reserved cooking water. Adjust seasoning with salt and pepper as needed.
Step 8: Spoon the celeriac mash onto warm plates, top each with a salmon fillet, and drizzle over the remaining mustard dressing. Serve immediately.

Tips & Variations

For extra creaminess, add a knob of butter or a splash of cream when mashing the celeriac.
Try swapping baby spinach for kale or Swiss chard for a different leafy green flavor.
If you prefer a stronger mustard flavor, increase the mustard quantity slightly in the dressing.
Serve with a wedge of lemon on the side for an added citrus boost.

Storage

Store any leftover celeriac mash and salmon separately in airtight containers in the refrigerator for up to 2 days. Reheat the mash gently on the stovetop or in the microwave with a splash of water to loosen it, and warm the salmon briefly to avoid drying out.