Prepare the filling. In a large bowl, combine the pork, fat (if using), fish sauce, soy sauce, sugar, makrut lime leaves, lemongrass, coriander and spring onions. Add the nam prik (curry paste) and mix thoroughly until evenly combined. Adjust the seasoning as you like.

Preheat the oven to 200C and line a baking tray with baking paper. Lay the pastry sheets on a clean surface and place half the filling in a log shape along the centre of each sheet. Fold the pastry over the filling to enclose it, pressing the edges to seal. Slice each log into six pieces to make 12 sausage rolls.

Transfer the sausage rolls to the prepared baking tray, seam-side down. Brush the tops with the beaten egg, sprinkle with sesame seeds and bake for 25 to 30 minutes or until the pastry is golden brown and the filling is cooked through. Let the sausage rolls cool slightly before serving.

For the sausage mince, combine all the sausage mince ingredients thoroughly, then with damp hands form into sausage shapes about 10 to 12cm long. Grill the sausages for 10 to 15 minutes, turning regularly until fully cooked and slightly charred on the outside.

While the sausages cook, heat the oil in a frying pan and add the sliced onions. Brush with the soy sauce and stir-fry for five to seven minutes until caramelised and slightly charred.

To serve, place a grilled sausage on a slice of white bread and add a generous amount of fried onions on top. Drizzle with smoky tomato chilli sauce and garnish with fresh coriander if using.