Method:
Break down the broccoli into large bite-sized florets. Keep aside. Prepare a bowl with ice water. Bring a saucepan of water to boil over high heat. Season with salt and add the bicarbonate of soda. This will help the broccoli retain a bright green colour.
Drop the florets in the boiling water and blanch for 2 minutes. Quickly remove them from the water and transfer to the ice-cold water to stop the cooking process. Once cooled, place onto a platter and cover until needed. Preheat the barbecue to high heat.
In a bowl, whisk the tahini, honey, lemon juice, and garlic. Season with salt and pepper. Whisk in the water, half a tablespoon at a time until the sauce becomes smooth, then add the sesame seeds, check the seasoning and set aside.
Once the barbecue is ready to use, drizzle some oil on the broccoli then place the florets on the barbecue over direct heat (or on a very hot ridged griddle pan) for 3 minutes on each side, until slightly charred and smoky. Remove from the barbecue and transfer to a serving platter. Drizzle on the dressing and add some extra sesame seeds.