In a dry pan over medium heat, toast the coriander and white peppercorns until fragrant. Place in a mortar and pestle or spice grinder and finely grind. Set aside.
In a blender or food processor combine the coconut aminos, garlic, and lemongrass. Blitz until the garlic and lemongrass are finely minced and no large pieces remain. Pour mix into a bowl.
To the blended mix add the remaining marinade ingredients and whisk. Place the beef strips in and marinade for at least 30 minutes but up to 6 hours.
Skewer the beef strips and grill over direct high heat until desired charring and inside temperate are reached.
Serve warm with rice, fresh herbs and vegetables, and spicy lime dressing.