In a bowl, combine ½ cup softened butter, ¼ tsp salt, ¼ tsp garlic powder, 2 tsp minced garlic, and ¼ cup of fresh parsley. Mix ingredients together using a fork or hands.
Carefully cut the bread in half lengthwise and evenly spread the butter over the inside of both halves.
Separately place each piece of garlic bread buttered side down onto a sheet of aluminium foil. Then fold over the foil and wrap the bread tightly.
Set up the Weber Q for indirect cooking by using a convection tray and trivet. Preheat by turning the gas control knob to the START/HI position. Family Q: Turn both gas control knobs to the START/HI position. Preheat with the lid down for 10 minutes.
Place both pieces of garlic bread onto the trivet buttered side down for 10 minutes. Turn the gas control knob down to the medium position. Family Q: Turn the small gas control knob off and the large gas control knob down to the medium position. Cook for 180°C (355°F) and 200°C (390°F) for 10 minutes.
After 10 minutes, remove the garlic bread from the Weber Q. Carefully open the foil, then flip over both halves using tongs, and sprinkle parmesan and mozzarella cheese over the top. (Do not close the aluminium foil)
Pop both halves of garlic bread back into the Weber Q and turn the heat up to medium/High. Cook for a further 10 minutes to allow the cheese to melt and the edges of the bread to get crispy.
Slice garlic bread into fingers, and serve with a sprinkle of fresh parsley over the top.