1. Rinse scallops, and pat dry. Pull muscle from side of scallops, and discard. Season with pepper, to taste.
2. Heat 2 teaspoons olive oil in a medium nonstick or well-seasoned cast-iron skillet over moderately high heat. Cook scallops, turning once, 4 minutes (depending on size of scallops) or until golden brown and cooked through. Transfer to a plate; cover and keep warm.
3. Lower heat to medium; add remaining 1 teaspoon oil to skillet. Cook bell pepper, shallot, and garlic, stirring occasionally, 4 minutes or until slightly softened.
4. Stir in the corn and edamame, and cook, stirring occasionally, an additional 4 minutes or until vegetables are tender.
5. Add the cider vinegar, and cook, stirring constantly, until completely evaporated, about 1 minute. Pour in the buttermilk; cook, stirring, until reduced in half. Stir in chopped tarragon, and spoon vegetables into 4 bowls. Top evenly with scallops; serve immediately.