Red & white potato salad with pickled onions

• red Roseval new potatoes↗1 ¼kg 1 ¼kg
• large red onion↗1 1

  halved and cut into thin half-moons

• white wine vinegar↗100ml 100ml
• soured cream↗150ml 150ml
• mayonnaise↗3 tbsp 3 tbsp
• Dijon mustard↗1 tbsp 1 tbsp
• celery↗2 2

  stalks, finely diced

• gherkin↗1 1

  from a jar, finely chopped

• dill↗2 tbsp 2 tbsp

  chopped

Step-by-step instructions

1. 1

   Put the potatoes in a pan of cold salted water and bring to the boil. Simmer for 15 mins or until tender and a knife goes in easily. Meanwhile, combine the onion and vinegar in a large bowl, cover and set aside.

2. 2

   Drain the potatoes and return to the pan, then stand for 5 mins to steam-dry. Slice them into bite-sized pieces and add to the bowl with the onion and vinegar, season with salt to taste and toss to combine. Cover and chill until cold.

3. 3

   Combine the soured cream, mayonnaise and mustard, then add to the cold potatoes with the celery, gherkin and dill. Stir with a spatula until well combined, taking care not to break up the potatoes too much. Season to taste, then chill for at least 1 hr before serving.