Steam the cauliflower florets until very tender, about 10-12 minutes.
Transfer steamed cauliflower to a blender or food processor, add half of the ghee and a pinch of sea salt, and process until creamy and smooth.
Pat the salmon fillet dry with a paper towel and season both sides with salt and black pepper.
Heat a non-stick skillet over medium-high heat with the remaining half tablespoon of ghee.
Place the salmon in the pan skin-side down and sear for 4-5 minutes until the skin is golden and crisp.
Carefully flip the salmon and cook for another 2-3 minutes until the fish is opaque and flakes easily.
Remove the salmon from the pan and set aside to rest.
In the same skillet, add the minced garlic and sauté for 30 seconds until fragrant.
Add the fresh spinach to the skillet and toss for 1-2 minutes until just wilted.
Stir in the lemon juice and remove from heat.
Plate the cauliflower mash, top with the sautéed spinach, and place the seared salmon on top.