Cook the potatoes in boiling water for 10-15 minutes, then drain. Make the dressing by whisking together the oil, lemon juice, mustard and some seasoning if you want.
Put all the other ingredients, including the warm potatoes, in a large bowl. Drizzle over the dressing and lightly toss. Serve immediately.
Recipe from Good Food magazine
450g new potatoes, halved
6 tbsp olive oil
juice of ½ lemon
1 tbsp wholegrain mustard
2 x 150g balls mozzarella, drained and torn
180g bag baby leaf spinach
200g tub roasted peppers in olive oil, drained and torn
handful of fresh basil