Rinse scallops and pat dry with paper towels. Sprinkle with salt and pepper. Trim root and stem ends off radishes. Rinse radishes and pat dry with paper towels. Cut each radish into quarters. Set aside. Combine broth and cornstarch in a cup; stir until smooth. Set aside. Heat the wok over high heat about 1 minute or until hot. Add 1 1/2 tablespoons of butter and swirl to coat bottom. Arrange half the scallops in a single layer in the wok, leaving 1/2 inch between (scallops should not touch). Cook scallops until browned on both sides. Remove scallops to a large bowl. Repeat with the remaining 1 1/2 tablespoons of butter and scallops. Reduce heat to medium high. Add radishes to wok; stir fry about 1 minute or until crisp tender. Remove radishes to the bowl with the scallops. Add wine to the wok. Stir cornstarch mixture; add to the wok. Add snow peas and bamboo shoots; heat through. Return scallops and radishes to the wok; stir fry until heated through. Serve scallop mixture over couscous on a serving platter.