Marinated Swordfish with Corn Succotash and Mashed Sweet Potatoes

Name: Marinated Swordfish with Corn Succotash and Mashed Sweet Potatoes
Ingredients: 4 Swordfish steaks, about 3/4 thick each and 6 to 8 ounces each; kosher salt and freshly ground black pepper; 3 Tablespoons butter; Extra-virgin olive oil; 2 Tablespoons fresh lemon juice; 1 Tablespoon chopped fresh rosemary; 3 Tablespoon dry white vermouth or white wine; 1 1/2 pounds sweet potatoes, peeled and cut into chunks; 1/4 cup heavy cream; Pinch of nutmeg; 1 Tablespoons brown sugar; 8 ounces (about 2 cups) frozen corn, thawed; 8 ounces (about 2 cups) frozen green beans, thawed (you can substitute with lima beans, if you prefer); 1 red bell pepper, seeded and diced; 1 medium red onion, finely chopped; 2 plum tomatoes, diced; 2 garlic cloves, minced; 1 Tablespoon finely minced chives