Put the potatoes into a pan of lightly salted water, bring to the boil, then cook for approx 15 minutes, until tender.
Meanwhile, mix 1 Tbsp pesto with the lemon juice.
When the potatoes are cooked, drain and put them back into the pan. Drizzle the pesto mixture over them and toss well. Season to taste with salt and pepper. Add more pesto if you like.
Transfer the potatoes into a serving dish, add the peppadews (if used), olives, tomatoes and mozzarella pieces.
Toss well, season with more pepper and serve or chill for later.