Equipment
* optional
Ingredients
Mustard Potatoes
- 600 g yukon gold potato, unpeeled, scrubbed, cut into 2 cm cubes
- 30 ml olive oil, extra virgin
- 25 g wholegrain mustard
- 15 g dijon mustard
- 2 garlic, minced
- 3 g fine sea salt
- 1 g black pepper, freshly cracked
Horseradish Salmon
- 680 g salmon fillet, skin-on, pin bones removed, cut into 4 equal 170g portions
- 60 g mayonnaise, full-fat
- 30 g prepared horseradish, drained of excess liquid
- 15 g dijon mustard
- 2 g lemon zest, finely grated
- 2 g fine sea salt
Garnish and Serving
- 8 g fresh dill, finely chopped, stems removed
- 1 lemon, cut into 4 wedges
Nutrition (per serving)
Nutrition is estimated per serving. Nutrients without complete source data are omitted.
Full nutrition
- Calories
- 611 kcal
- Protein
- 35 g
- Carbohydrates
- 27 g
- Fat
- 40 g
- Zinc
- 1.2 mg
Sources: Aggregated Public Data, USDA FoodData Central
Method
Preheat the oven to 200°C (400°F) and position an oven rack in the center. Line a rimmed baking sheet with parchment paper.
Place the scrubbed Yukon Gold potatoes on a cutting board and cut them into uniform 2 cm (0.75-inch) cubes using a chef's knife.
In a large mixing bowl, combine the diced potatoes, olive oil, wholegrain mustard, 15g of dijon mustard, minced garlic, 3g of fine sea salt, and black pepper until the potatoes are thoroughly coated.
Spread the seasoned potatoes into a single layer across the lined rimmed baking sheet and roast at 200°C (400°F) for 12 minutes until they just begin to soften around the edges.
In a small mixing bowl, whisk together the mayonnaise, drained prepared horseradish, remaining 15g of dijon mustard, lemon zest, and half of the chopped dill (4g) until a smooth, thick emulsion forms.
Thoroughly pat the salmon fillets dry on all sides using paper towels to remove surface moisture, then season the flesh evenly with 2g of fine sea salt. Wash hands, utensils, and work surfaces thoroughly to prevent cross-contamination.
Spread the horseradish mayonnaise mixture evenly over the top flesh of each salmon fillet using a pastry brush or the back of a spoon, creating an even coating approximately 3 mm thick.
Remove the baking sheet from the oven. Using a spatula, push the par-roasted potatoes to the perimeter of the sheet, arrange the coated salmon fillets skin-side down in the center, and roast at 200°C (400°F) for 13 minutes until the fish reaches an internal temperature of 63°C (145°F) on an instant-read digital thermometer inserted into the thickest section.
Transfer the rimmed baking sheet to a heatproof surface and let the salmon rest undisturbed for 2 minutes to allow internal moisture to stabilize.
Garnish the roasted potatoes and salmon fillets with the remaining 4g of chopped fresh dill, and serve hot accompanied by fresh lemon wedges.
Chef's Notes
- Draining prepared horseradish through a fine-mesh strainer or squeezing it gently in a clean paper towel prevents excess brine from breaking the mayonnaise emulsion during baking.
- The fat in the mayonnaise acts as an insulating blanket, protecting delicate salmon proteins from direct hot air and keeping the interior exceptionally moist.
- Leaving the skin on the salmon provides a natural barrier against the hot sheet pan, keeping the bottom tender and making portion transfer effortless with a fish spatula.
- Yukon Gold potatoes are ideal for this sheet-pan technique because their medium-starch, waxy profile retains structural integrity and absorbs the acidity of the mustard glaze without falling apart.
Storage
Refrigerator: 3 days — Store in an airtight glass or BPA-free container within 2 hours of roasting.
Reheating: Preheat oven to 150°C (300°F). Place salmon and potatoes on a baking sheet and heat until warmed through to an internal temperature of 74°C (165°F), approximately 10 to 12 minutes.
Troubleshooting
Salmon is dry and white albumin deposits heavily on the sides
Cause: The salmon roasted past the recommended safe internal temperature of 63°C (145°F).
Fix: Cannot be fixed once fully overcooked; spoon any pan juices and a squeeze of fresh lemon over the fillets to restore surface moisture.
Prevention: Begin testing the internal temperature at the 10-minute mark of the combined roast using an instant-read digital thermometer.
Potatoes are still hard while the salmon is already cooked
Cause: Potatoes were cut larger than 2 cm or were not given the full 12-minute initial par-roast.
Fix: Transfer cooked salmon to a warm plate covered loosely with foil, then return potatoes to the oven at 220°C (425°F) for 5 to 7 minutes until tender.
Prevention: Cut potatoes into uniform 2 cm pieces and ensure oven is fully preheated before par-roasting.
Horseradish mayonnaise topping slid off the salmon into the pan
Cause: The salmon fillets were wet when the topping was applied, or excess moisture in the prepared horseradish diluted the mayonnaise emulsion.
Fix: Spoon the warm melted sauce from the sheet pan directly back over the fillets before serving.
Prevention: Press paper towels firmly against the fish flesh before seasoning and drain jarred horseradish in a fine sieve before mixing.
Cultural Context
Pairing rich, oily fish like salmon with sharp, sinus-clearing horseradish and pungent mustards is a traditional cornerstone of Central and Northern European culinary traditions. This dish adapts those classic Scandinavian and Germanic flavor affinities into a contemporary American one-pan weeknight preparation that balances bold pungency with rich fats.
