Preheat your grill to medium-high heat.

In a large pot, cover the baby potatoes with water and add a pinch of salt. Bring to a boil and cook for about 15-20 minutes, or until the potatoes are fork-tender.

Drain the potatoes and let them cool slightly. Once cool enough to handle, gently smash each potato with the bottom of a glass or a potato masher.

In a small bowl, mix together the olive oil, minced garlic, chopped rosemary, salt, black pepper, and red pepper flakes (if using).

Brush the smashed potatoes with the garlic rosemary oil mixture on both sides.

Place the potatoes on the grill and cook for about 5-7 minutes on each side, or until they are crispy and golden brown.

Remove the potatoes from the grill and garnish with fresh rosemary sprigs before serving.