Grilled Salmon with Mustard Dressing

4 salmon steaks or thick filets
Extra-virgin olive oil
Hot or peppered olive oil (optional)
1 tablespoon fennel seed, toasted
2 teaspoons powdered ginger

2 bags triple-washed spinach
Kosher salt

DRESSING
1 tablespoon Dijon or country style mustard
1/4 cup raspberry-flavored vinegar (available in most supermarkets)
2 teaspoons crushed capers
1 large radish, finely chopped
3/4 cup extra-virgin olive oil

PREPARE SALMON:
Rinse the steaks and pat dry with paper towels. Place steaks in bowl and drizzle with the oils to coat. (Adjust the ratio of the hot pepper oil if you prefer more snap.) Thoroughly grind the fennel seed in a small electric coffee grinder or with a mortar and pestle. Combine with the powdered ginger and rub well onto the steaks. Cover and marinate half an hour. Meanwhile, make the vinaigrette.

MAKE DRESSING:
Combine all dressing ingredients in a jar. Cover and shake until emulsified. Taste and correct if desired. (The dressing can be made ahead but should be brought to room temperature before serving.)

Grill the salmon steaks over medium-hot heat, turning once, until cooked through.

PREPARE SPINACH
Place the spinach in a small pot with 1/2 cup of salted water. Cook, stirring over medium-high heat, until the spinach is just wilted. Remove and strain.

Arrange a bed of spinach on a serving platter, top with the grilled salmon and drizzle with the dressing.