Crispy Rosemary Butter Roasted Potatoes

Bahan-bahan (6 porsi)

• 3 pounds small Yukon gold potatoes
• 6 tablespoons salted butter, melted
• 1 tablespoon chopped fresh rosemary, plus 3 rosemary sprigs
• 4 -6 cloves garlic, smashed
• kosher salt and black pepper
• flaky sea salt for serving