Heat olive oil in a large skillet or sauté pan over medium-high heat. Meanwhile, season scallops with salt and pepper, then dredge in flour. Use a sieve to shake off excess.
Add dredged scallops to pan in a single layer. Cook for 2-3 minutes on one side, allowing the scallops to brown, then turn them and cook for another minute.
Add butter to pan, then add shallots and garlic. Cook for another minute.
Add parsley, white wine and lemon juice. Cook for another minute, or so. — Sauce should be somewhat thickened at this point, but if not, remove scallops with a slotted spoon (to avoid overcooking) and continue simmering sauce until reduced slightly, another 2-3 minutes.
Add scallops back to sauce. Toss to coat. Serve immediately.