Heat a grill pan over high heat for 2 minutes and place the beef slices onto the surface for 1 minute per side. Remove immediately and set aside
Whisk the hoisin, ketchup, barbecue sauce, nam pla, soy sauce, ginger, vegetable oil, scallions and cilantro together in a large bowl. Add the grilled beef and refrigerate at least 1 hour to let the flavors blend.
Remove from the refrigerator and thread one piece of beef onto a 6" bamboo skewer. Repeat with the remaining beef, set onto a decorative platter and garnish with chopped cilantro.