Infuse minced rosemary in olive oil for 1 minute in a frying pan over medium heat. Reserve the infused oil in a heat-resistant bowl.
Place the Bocconcini cheese in a bowl and sprinkle with Espelette pepper. Mix thoroughly to distribute. Set aside.
Barbecue option: For even more flavour, grill the pineapple quarters on the oiled grill of a barbecue on high until they become caramelized, around 2 minutes on all sides.
Frying pan option : In the same frying pan you used to infuse the oil, fry the pineapple quarters on high heat for around 2 minutes, or until they take on an attractive caramelized colour. Flip the quarters and fry the other side.
Next, cut the pineapple quarters into 3 cm cubes and drop them into the infused oil. Let cool.
Remove the bottom leaves from the rosemary stems and use each to skewer a Bocconcini cheese, a pineapple cube and a slice of prosciutto.
Place on a serving dish and drizzle with infused oil and balsamic reduction.