Remove side muscle from scallops and pat completely dry. Let sit on paper towels 10-15 minutes. Season with salt and pepper just before cooking.
Heat large skillet over medium-high to high heat for 3-4 minutes. Add oil and heat until shimmering.
Sear scallops without moving for 2-3 minutes until golden brown. Flip and cook 1-2 minutes more until just done.
Remove scallops and reduce heat to medium-low. Add garlic and cook 30 seconds until fragrant.
Add cold butter and swirl to melt. Add lemon juice and parsley, swirling to combine.
Return scallops to pan and spoon sauce over. Serve immediately while hot.
