Quick smashed Greek potatoes with feta and rosemary

Name: Quick smashed Greek potatoes with feta and rosemary
Prep time: 7 min
Cook time: 25 min
Total time: 32 min
Cuisine: Greek
Ingredients: 8-12 medium potatoes (roasting potatoes); 7 oz (200g) feta cheese (crumbled); 3 tbsp small capers or sliced black olives; 2 large whole cloves of garlic, (sliced); 1 red onion (sliced into very thin rounds); small rosemary sprig (torn); 1 lemon (cut into quarters); olive oil to drizzle; salt and pepper to season