Prep the Brussels sprouts by using your fingers to separate individual leaves. Wash the leaves thoroughly and set them aside.
Place the scallops into a bowl and season them with smoked applewood sea salt and pepper, gently toss to coat.
Heat two tablespoons olive oil in a non-stick saucepan over high heat. Place the scallops flat down onto the saucepan and cook, flipping once, until browned, about 3 minutes on each side.
Meanwhile, heat one tablespoon of olive oil in a non-stick saucepan over medium-high heat. Add the Brussels sprout leaves and red pearl onion, season with lemon juice, sea salt, and pepper. Sautee for 2 minutes, until warmed and just cooked but before they begin to wilt. Remove from heat.
Transfer the scallops and Brussels leaves onto a serving plate and serve immediately.