Step 1

Spray a frying pan with cooking spray and place over low heat. Add the onion and thyme. Cover and cook for 10-15 minutes until soft and slightly golden. Stir occasionally, adding a splash of water if necessary.

Step 2

Remove the lid and stir in the vinegar, sugar, and water. Cook for a further 5 minutes until the liquid has almost evaporated and the onion is soft and sticky. Season to taste.

Step 3

Place 1 sausage in each roll and top with the onion. Sprinkle over the extra thyme and serve.

Step 4

Serving size: 1 hot dog