Step 1: Preheat oven to 200C. Line 2 baking trays with baking paper.
Step 2: Preheat grill on medium-high. Cook sausages under preheated grill, turning, for 6-8 minutes or until golden brown and cooked through. Remove from grill and set aside to cool.
Step 3: Use a small sharp knife to cut the pastry into 1cm-thick strips. Lightly brush pastry with a little egg. Wrap 2-3 pastry strips around each sausage to resemble bandages, leaving a little gap at one end for the face. Trim and discard excess pastry. Place on the lined tray. Repeat with remaining sausages, pastry and egg.
Step 4: Bake in preheated oven, swapping trays halfway through cooking, for 20-25 minutes or until golden brown and puffed. Remove from oven and set aside to cool slightly. Use the American mustard to decorate the mummies with eyes. Place on a serving platter, serve with mustard and tomato sauce.
The kids will love these cocktail sausage mummies.