Put all the ingredients for the marinade in tupperware and stir until sugar is completely melted. Add beef cubes, cover and refrigerate for at least 3 hours (no more than 7). Preheat oven to 350ºF. Soak wooden skewers in water for about 30 minutes, to prevent them from burning. Thread beef and vegetables onto skewers and lay them on a sheet tray covered with aluminum foil. Bake for 20-25, until beef is cooked through and golden brown. Serve.