Remove the rump steaks from the fridge about 20 minutes before cooking to bring them to room temperature.
Preheat a BBQ or grill plate to high heat.
Brush the steaks lightly with olive oil and season both sides with sea salt and cracked black pepper.
Place the steaks on the hot BBQ and cook for about 3–4 minutes each side for medium rare, depending on thickness.
Transfer the steaks to a board, loosely cover with foil and rest for 5 minutes.
While the steaks cook, brush the corn with olive oil and place on the BBQ. Turn occasionally until lightly charred and cooked through.
To make the garlic butter, combine the softened butter, garlic, parsley, lemon juice and a pinch of salt in a small bowl and mix well.
Serve the rested rump steaks topped with garlic butter alongside the grilled corn and a simple salad.