Thaw the salmon fillets, pat dry.
Preheat oven at 425 degrees F and line a baking sheet with aluminum foil.
Season the fish with salt and pepper on both sides. Set aside.
Pulse the walnuts in a food processor to fine crumbs.
Place the crumbs on a shallow dish. Press the salmon fillets into the walnut crumbs to coat on all sides.
Transfer them to the baking sheet with a drizzle of olive oil.
Bake the fillets in the oven for 10 minutes. Turn the broiler on high and broil for 3 minutes until golden brown.
Remove them from the oven allowing to rest for 3 minutes.
Serve the salmon fillets over spinach greens and cherry tomatoes on the side.