Extra-virgin olive oil
1 1/2 pounds lean ground beef
2 cloves garlic, minced
1 tablespoon tomato paste
2 tablespoons all-purpose flour
2 cups diced white button mushrooms
1/2 yellow onion, finely diced
1 medium carrot, finely diced
1 cup low-sodium beef stock
2 tablespoons Worcestershire sauce
1 cup frozen peas, thawed
3/4 cup freshly grated packaged mozzarella cheese
1 16 oz packet phyllo pastry
1 stick unsalted butter, melted
1/2 cup grated Parmigiano Reggiano