Steak with Wine Sauce and Potato Gratin

INGREDIENTS

• Butter, for baking dish
• 1 1/2 cups heavy cream
• 5 ounces soft goat cheese, crumbled
• 1 garlic clove, minced
• Coarse salt and ground pepper
• 1 1/2 pounds baking potatoes (about 3)
• 4 flatiron or top blade steaks (6 to 8 ounces each and 1 inch thick)
• 1 cup dry white wine
• 1 tablespoon Dijon mustard
• 2 tablespoons capers, drained