Pre-heat the BBQ for 3-4 minutes with the lid on, over a medium-low heat.
Trim and half the brussels sprouts, then add them to a Tapas Dish with 2 tbsp warm water. Place on the BBQ Grid and cook for 2-3 minutes.
Drain any excess water then add the garlic, cream and season with salt and pepper.
Top with the breadcrumbs, gruyere and a grate of fresh nutmeg then bake on the BBQ with the lid on for around 12-15 minutes until bubbling.