Make sure the small side muscle from the scallop (most scallops are sold with the muscle already removed.) Rinse with cold water and pat dry with paper towels.
Heat a large non-stick skillet over medium-high heat for 1 to 2 minutes. Add oil and ghee and heat until quite hot. Gently add the scallops in a single layer and not touching each other. Salt and pepper to taste.
Sear on each side for 2 to 3 minutes until a golden crust is formed.
Take the skillet off the heat and transfer the scallops to a plate; keep warm. Let the skillet cool a minute before making sauce.
Return the skillet to medium heat. Add 1/2 tablespoon of the ghee and the shallots and sauté until softened, 1 to 2 minutes. Add the chicken stock and simmer until reduced by one half, another 1 to 2 minutes. Add the herbs and lemon zest. Reduce the heat to low and add the remaining butter. Whisk constantly until the butter is melted. Return the scallops to the skillet and using tongs, gently roll them in the sauce to warm them through. Serve immediately with lemon wedges on the side.