Preheat your oven to 400°F (200°C).
In a large mixing bowl, combine the halved baby potatoes, olive oil, dried oregano, salt, black pepper, and red pepper flakes if using. Toss until the potatoes are well coated.
Spread the seasoned potatoes in a single layer on a large baking sheet.
Scatter the smashed garlic cloves and crumbled feta cheese over the potatoes.
Roast in the preheated oven for 30-35 minutes, or until the potatoes are golden brown and crispy, stirring halfway through for even cooking.
Once done, remove from the oven and let cool for a few minutes. Garnish with fresh parsley before serving.