Crush anise seeds and combine with ground ginger, white pepper, black pepper, and salt in a small bowl.

Brush olive oil over swordfish steaks.

Rub the anise seed mixture over both sides of the steaks.

Prepare grill to medium-high heat.

Place steaks on the grill rack.

Grill for 5 minutes on each side, or until fish flakes easily when tested with a fork.

Set aside grilled swordfish steaks.

Combine trimmed watercress and thinly sliced red onion in a large bowl.

In a jar, combine rice wine vinegar, low-sodium soy sauce, minced fresh ginger, dark sesame oil, water, sugar, and black pepper.

Cover the jar tightly and shake vigorously to emulsify.

Pour the dressing over the watercress and red onion mixture.

Toss gently to coat.

Arrange watercress mixture on a platter.

Top with grilled swordfish steaks.

Sprinkle the steaks with toasted sesame seeds.