Cut the salmon portions into squares, season with garlic salt and parsley.
Spray or brush olive oil to the grill rack and heat.
Assemble the skewers and place them on the grill with rosemary sprigs between them.
Cook the salmon for about 4 minutes on each side.
In a saucepan over medium heat bring the milk, butter, chicken cube, garlic salt and cornstarch to a boil stirring constantly, lower the heat and continue cooking and stirring until the sauce thickens.
Serve with Tostones de pana (fried breadfruit) or green plantains.