Combine the arrowroot starch and half of the salt and pepper in a shallow bowl. Pat the salmon filets dry, and working with one at a time, toss with the arrowroot starch to coat. Set aside.
Using a large, deep pan, melt 1 tbsp ghee over medium heat. Once the ghee is melted and shimmering, add the salmon to the pan skin side down. Sear the salmon for about 4 minutes on each side or until crisp and cooked through. Set aside on a plate and cover with foil to keep warm.
Add the white wine to the pan and scrape with a wooden spoon to remove any burnt bits from the bottom.
Reduce the heat to medium-low Add another tablespoon of ghee to the pan. Once melted, add the onion, shallot and garlic and saute for 4-5 minutes or until the onion is lightly fragrant and the onion is translucent.
Add the broth and most of the lemon juice to the pan and whisk well and bring to a low boil. Add the orzo, the remainder of the salt and pepper, and frozen peas. Stir well. Reduce to a low simmer. Cover and simmer on low for 10 minutes, stirring often to allow the orzo to cook through.
Add the coconut milk and spinach. Stir well once the orzo is tender and the spinach begins to wilt.
Add the salmon back to the pan and cover for 3 minutes to allow the salmon to reheat.
Top the dish with the reserved lemon juice along with chopped parsley and lemon slices!