Heat 1 tablespoon of the oil in a large skillet over medium-high heat. Brush honey mustard all over salmon. Season both sides of salmon with onion flakes and black pepper. Place cashews in a shallow dish, add four of the salmon fillets and turn to coat.
Place all salmon fillets in hot skillet and cook 3 minutes per side, until fork-tender.
Heat remaining olive oil in separate large skillet over medium heat. Add garlic and cook 1 minute. Add bok choy and cook 2 minutes, until greens wilt but stalks are still crisp-tender. Season, to taste, with salt and pepper.
Serve the cashew-crusted salmon with this meal and reserve 2 uncrusted fillets for another meal.