Cabbage Steaks with Creamy Mushroom Sauce

Name: Cabbage Steaks with Creamy Mushroom Sauce
Ingredients: 1 medium head green cabbage ( 3 pounds ); 5 tablespoons extra-virgin olive oil , divided; 2 teaspoons Italian seasoning; ½ teaspoon ground pepper , divided, plus more for garnish; ¼ teaspoon salt plus ⅛ teaspoon , divided; 8 ounces mushrooms , sliced (about 3 cups ); 1 large shallot , finely chopped; 3 cloves garlic , finely chopped; 2 teaspoons fresh thyme leaves; ½ cup dry white wine; 1 cup half-and-half; ¼ cup grated Parmesan cheese; Thinly sliced fresh chives , for garnish (optional)