Preheat oven to 220 C / 420 F. Line 3 large baking trays with baking paper. Set aside.
Squeeze out excess liquid from onions. Set aside.
Place beef, onions, carrots, garlic, breadcrumbs, parsley, paprika and tomato sauce (ketchup). Season with salt and pepper. Stir to combine. Divide into 8 equal portions. Set aside.
Cut each puff pastry sheet in half. Place one portion of mince across the long side of pastry. Roll pastry over mince to enclose.
Brush with egg. Sprinkle with sesame seeds if you like.
Cut into 4 equal rolls. Place the rolls in the baking tray in a single layer, seam side down.
Repeat with the remaining pastry and filling mixture. Bake for 30 minutes or until golden and cooked through.
Serve with tomato sauce (ketchup)