Preheat oven to 200°C/180°C fan-forced. Line 2 large baking trays with baking paper.

Combine mince, tomato sauce, barbecue sauce, breadcrumbs, mustard powder, onion and carrot in a bowl.

Cut each pastry sheet in half. Shape 1/2 cup mince mixture into a sausage shape. Place along 1 long side of 1 pastry half. Roll up pastry to enclose filling. Using fingertips, pinch pastry to seal. Cut into quarters. Place, seam side down, on 1 prepared tray, 5mm apart. Repeat with remaining mince mixture and pastry.

Bake for 35 minutes or until golden and cooked through. Serve with tomato sauce.

Divide the sandwiches among serving plates. Drizzle over the sauce to serve