01In a small sauté pan, heat olive oil over medium-low heat. Add the chopped rosemary and crushed red pepper flakes, if using, and sauté until fragrant, about 30 seconds. Remove from heat and place infused oil in a large bowl.
02Heat the grill to medium-high. Coat the grill grate with oil to help prevent sticking. Toss pineapple cubes in the oil mixture. Thread pineapple cubes on the wet skewers. Grill pineapple for about 5-10 minutes, turning to create grill marks on each side. Remove from heat and let cool.
03Toss the bocconcini balls in the remaining infused oil. Thread a bocconcini ball and a cube of pineapple on each spring of fresh rosemary. Repeat with remaining sprigs.
04Place on a platter and refrigerate for at least 15 minutes to chill before serving.