Preheat the oven to 350°F (175°C).

Line a large baking sheet with parchment paper to prevent sticking and ensure an easy cleanup.

In a food processor, place the 1. 0 cup (3. 5 oz / 100g) of walnuts and pulse briefly until they are roughly chopped.

Add the chopped dill, grated lemon rind, garlic salt, black pepper, and melted butter to the walnuts in the processor. Pulse until the ingredients combine into a crumbly mixture.

Place the salmon fillets onto the prepared baking sheet in a single layer, making sure the skin-side is facing down.

Evenly rub the top of each salmon fillet with the Dijon mustard, using about 1. 0 tbsp (0. 5 oz / 15g) per fillet.

Spoon the prepared walnut mixture equally over each fillet. Gently press the mixture down into the surface of the salmon so it adheres to the mustard layer.

Bake in the preheated oven for 15 to 20 minutes, or until the salmon easily flakes with a fork and the crust is lightly golden.

Remove the baking sheet from the oven and carefully transfer the salmon fillets onto serving plates.

Drizzle the 4. 0 tsp (0. 7 oz / 20g) of fresh lemon juice evenly over the hot fillets and serve immediately.

Pat the Fish Dry: Before applying the Dijon mustard, use a paper towel to thoroughly pat your salmon fillets dry. This helps the mustard bind to the fish and prevents the walnut crust from becoming soggy.

Don't Over-Process the Crust: When pulsing the walnuts in your food processor, aim for a rough chop rather than a fine powder. Leaving some texture ensures that beautiful, buttery crunch that makes this Walnut Crusted Salmon so irresistible.

Let It Rest: Give your salmon about 3 to 5 minutes to rest on the baking sheet after removing it from the oven. This allows the juices to redistribute and helps the crust set perfectly before plating.