In a food processor or blender, prepare pesto cream by blending walnuts, garlic, basil and spinach for 30 seconds.
Add olive oil and almond cream and blend.
Add lemon zest and blend; set aside.
Heat macadamia nut oil in large sauté pan over medium heat and sear halibut filets on one side until a golden crust forms and the fish is done on the bottom, 1 to 2 minutes. Gently turn the fish and cover to finish cooking through, about 2 minutes. The fish is ready when it starts to flake.
While the fish is cooking, in separate small sauce pan, warm pesto cream on medium-low heat and reserve until fish is cooked.
Plate the fish, squeeze lemon juice over, if desired, and drizzle the pesto on top (about 2 tablespoons per dish). Enjoy!