Cabbage Roll Phyllo Pockets

Name: Cabbage Roll Phyllo Pockets
Ingredients: 6 cabbage leaves; 2 tablespoons olive oil; 1/2 large carrot, very finely diced; 1/2 celery stalk, very finely diced; 1/4 white onion, very finely diced; 1 clove garlic, minced; Kosher salt and freshly ground black pepper; 8 ounces ground pork; 1/2 teaspoon fresh oregano leaves, minced; 1/2 teaspoon fresh thyme leaves, minced; 1/3 cup beef broth; 1 1/2 teaspoons all-purpose flour; 1 1/2 teaspoons lightly packed light brown sugar; 8 frozen phyllo pastry sheets (13-by-17-inch), thawed; 1/2 cup (1 stick) unsalted butter, melted