Fresh fennel and fennel seeds flavor this elegant main course.
Stir fennel seeds in large nonstick skillet over medium heat until fragrant, about 1 1/2 minutes. Transfer seeds to small bowl; cool. Mix in butter, shallots, and 1 tablespoon fennel fronds; season butter mixture with salt and pepper.
Melt 1 tablespoon butter mixture in same large nonstick skillet over medium heat. Add sliced fennel bulb and 1/4 cup water to skillet; cover and cook until fennel is crisp-tender, about 8 minutes. Uncover skillet and sauté until fennel begins to brown, about 2 minutes. Transfer fennel to plate.
Sprinkle salmon with salt and pepper. Add 1 tablespoon butter mixture to same skillet and melt over medium heat. Add salmon; cover and cook 5 minutes. Turn salmon over; add 1/4 cup water to skillet. Cover and continue cooking until salmon is just opaque in center, about 5 minutes longer. Slide salmon to 1 side of skillet; return fennel to skillet. Add Pernod, 2 teaspoons butter mixture, and remaining 1 tablespoon chopped fennel fronds; stir to heat through.
Divide fennel mixture between 2 plates. Top with salmon; spoon remaining butter mixture over salmon.