Drizzle a little olive oil over the garlic bulb and season with 1/2 tsp salt. Wrap in foil and put on the grill close to the heat source, but not directly over the coals. Cook for 35-40 mins until soft, then leave until it’s cool enough to handle.

Squeeze half the roasted garlic out into a bowl and squash with a fork to make a paste. Stir in the tahini, 1/2 tsp sugar, 1/2 tsp salt and 1/2 tsp black pepper, and mix well. Stir in 4-5 tbsp water, or enough to make a pale, loose dressing.

Put a flameproof pan on the grill directly over the coals and cook the spinach for a few minutes, stirring until wilted and tender (you may need to do this in batches). Remove from the heat, drain off any excess water and stir into the tahini dressing before serving.