Hot dog wraps with fiery onion relish

Method

1. Begin by making the relish, as it can be served warm or cold. Heat the sunflower oil in a frying pan and cook the onions for 10 minutes until softened and lightly golden. Stir in the garlic and seeds and cook for 1 minute more. Add the sugar, ¼ teaspoon salt, vinegar and chilli and bubble for 5 minutes until the liquid evaporates.
2. Heat the hot dogs according to the packet instructions. Heat a large non-stick griddle or frying pan, and toast the flatbreads in batches, turning until golden and crisp. Put a hot dog, squirt of mustard (if using) and some relish on each, fold up and scatter with some watercress. Serve with paper napkins.