Place 1 tablespoon of oil in a large skillet and heat 1 minute until hot.
In a medium bowl, mix the honey and mustard together, add the onion and garlic; mix well.
Brush the salmon on the skin side with the honey mixture thick enough to coat. Place in the cashews and coat well.
Place the fish skin side down in the hot skillet and gently sauté until the side turns golden. Turn over the salmon and finish cooking it until the internal temperature reaches 145°F using a cooking thermometer.
Place on a platter and drizzle with the remaining oil and a squirt of lemon. Serve immediately.