Preheat oven to 375°F. Cut the endigia in half lengthwise and place into a bowl. Top with 3 tablespoons of the olive oil, rosemary and saba or balsamic vinegar. Season with salt and pepper. Place endigia in a casserole so they fit snugly and roast for approximately 20 minutes until golden and tender. Cool slightly. Pour cream over endigia, top with grated Parmigiano, then dot with butter. Place in oven until bubbly and golden brown. Serve warm.