Defrost 3 sheets of puff pastry and preheat oven to 400°F.
Squeeze the juice out of ½ cup of grated onion.
Place 1 lb. ground chicken, ½ cup of grated onion, ½ cup of grated carrot, 1 egg, 1 cup panko breadcrumbs, ¼ cup finely chopped cilantro, 2 finely sliced green onions, 2 tsp. ginger, and 1 tsp. each of salt and pepper in a large bowl.
In another small bowl, add 2 Tbsp. sweet chili sauce, 1 tsp. soy sauce, 1 tsp. fish sauce, 1 tsp. lime zest and juice of ½ a lime, and 1 tsp. fresh green chili, if using. Stir together, taste, and adjust flavors as you like.
Mix the sauce in with the ground chicken sausage mixture using your hand or a wooden spoon until well combined.
Lay out defrosted puff pastry on a board. Cut puff pastry in half longways, creating two equal-size sheets.
Spoon ½ of a cup of ground chicken mixture onto the longest edge of the puff pastry, forming a log. Carefully and tightly roll the puff pastry.
Using a pastry brush or your fingers, brush the edge of the puff pastry with 1 lightly beaten egg mixture to seal the roll together.
Brush the top of roll with egg mixture, and sprinkle over sesame seeds to taste.
Cut into 8 even pieces.
Using a pastry brush, brush the edge of the puff pastry with lightly beaten egg mixture to seal the roll together.
Brush top of roll with egg mixture, and sprinkle over sesame seeds.
Cut into 8 even pieces.
Repeat the process with remaining puff pastry and ground chicken, then lay onto a baking tray lined with parchment paper.
Bake 30 to 35 minutes, until the pastry is golden brown and chicken sausage has reached temperature (165°F is the fully cooked temperature for chicken).