Place the spinach, Holland House vinegar, pine nuts, Parmesan, lemon juice, garlic, lemon zest, salt and pepper into the bowl of a food processor and pulse several time.
With the food processor running, gradually drizzle in the olive oil. Stop and scrape the bowl occasionally.
Taste and season the pesto as needed.
Measure out 1/4 cup of the prepared pesto and spread over the salmon, coating all sides.
Preheat the grill to high heat.
Place the fish, skin side down, onto the grill and cook 6 - 8 minutes.
Flip the fish and cook an additional 5 minutes, or until cooked through and fish flakes with a fork.
Top with additional pesto if desired. Serve and enjoy!