Step 1:
Place the rack in the lower third of the oven and preheat the oven to 190°C (375°F). Line a large rimmed baking sheet with parchment paper or a non-stick mat.

Step 2:
Halve the 1 kg sweet potatoes lengthways, coat with 2 tbsp olive oil and ½ tsp salt and 1 tsp fresh black pepper, then transfer cut side down to the prepared baking sheet. At this step also add the whole garlic cloves to cook alongside the sweet potatoes. Cook sweet potatoes in the oven until very tender, about 30–35 minutes. 

Remove from the oven and let cool slightly.

Step 3:
In a bowl, combine 100 ml hot vegetable stock, 70 g tahini, and 1 tbsp white or red miso paste. Mix until smooth and creamy.

Step 4:
Scoop the warm flesh from the sweet potatoes into a large bowl. Squeeze the roasted garlic from their skins and add to the sweet potatoes. 

Step 5:

Mash the potatoes with a potato masher or, for a smoother purée, pass them through a potato ricer. Stir in 2 tbsp unsalted vegan butter, most of the creamy tahini mixture (reserve a little to drizzle over the top before serving), and season with salt and freshly ground black pepper to taste. Sprinkle with black and white sesame seeds (optional) Serve straight away whilst its warm.