Melt 2 teaspoons butter in a medium nonstick skillet over medium heat. Add the leek, salt, and pepper; cover and cook 10 minutes, stirring frequently. Set aside; keep warm.
Combine the wine, thyme, peppercorns, and bay leaf in a medium saucepan. Bring to a boil; cover, reduce heat, and simmer 5 minutes. Add scallops to wine mixture. Remove from heat, and let stand for 5 minutes. Remove scallops with a slotted spoon; keep warm. Strain wine mixture through a sieve into a bowl, reserving 1 cup. Discard the remaining wine mixture.
Melt 2 teaspoons butter in a small saucepan over medium heat. Stir in flour with a whisk; cook 2 minutes. Gradually add reserved wine mixture, stirring constantly with a whisk. Cook 5 minutes. Add half-and-half and curry, stirring with a whisk; cook 2 minutes or until thick. Add scallops to curry mixture; cook 1 minute or until thoroughly heated.
Divide the leek mixture evenly among 4 plates. Top with the scallop mixture.
Note: In this recipe, the meatiness of the scallops is enriched by the half-and-half and emboldened by the curry. Choose a wine that's round in the mouth and slightly buttery, but with a refreshing acidity running through it. A white Burgundy would be perfect. If price is no object, try the Chassagne-Montrachet from Bernard Morey ($28.50); if it is, try Louis Jadot's Maçon-Villages ($11).