Sweet & sour rainbow slaw

Ingredients

450g red and white cabbage (a mixture), very thinly sliced2 carrots peeled and sliced into thin matchsticks1 small red onion finely chopped1 celery heart, thinly sliced8 radishes topped and tailed, then thinly sliced or quartered1 red pepper cored, deseeded and thinly sliced2 tbsp white wine vinegarjuice 0.5 lemon2 tbsp light brown soft sugar1 tsp mustard powder½ tsp yellow mustard seeds½ tsp celery seeds½ tsp poppy seeds4 tbsp vegetable oil

Method