Subscribe to our magazine
Save 42% & receive a £10 M&S e-gift card!
To make the dressing, heat the oil in a pan, then throw in the mustard seeds and cook until they start to pop. Tip the seeds into a bowl and allow to cool. Add the rest of the dressing ingredients to the bowl and whisk everything together.
Add the tomatoes, onions, cucumber and radish to the dressing, stir to coat, then allow to stand at room temperature for 10 mins before serving.