Preheat oven to 475°F

Toss cucumber, vinegar, 1 tbsp dill 1 tbsp oil and salt and pepper together

In another bowl combine horseradish, remaining dill, panko and oil.

Place salmon on a baking sheet sprinkle with salt and pepper then top with panko mixture

Bake until golden brown on top, about 8 min

Toss spinach with cucumber, serve with salmon