• ½ onion, diced
• 2 garlic cloves, thinly sliced
• 15 g (½ oz) ginger, thinly sliced
• 20 ml (⅔ fl oz) vegetable oil
• 10 g (⅓ oz) sea salt flakes
• 250 g (9 oz/1⅔ cups) black sesame seeds
• 40 ml (1¼ fl oz) pomegranate molasses
• 3.5 g (⅛ oz) ground star anise
• 3.5 g (⅛ oz) ground fennel
• 0.5 g cayenne pepper
• 6 g (⅕ oz) caster (superfine) sugar
• 5 g (⅙ oz) methylcellulose
• 1.5 g (1/20 oz) xanthan gum
• 1 teaspoon lemon juice

Place the onion, garlic, ginger, oil and 2 g (1/16 oz) salt in a saucepan over medium heat and cook for 5 minutes. Add the sesame seeds and 1.1 litres (38½ fl oz) water and bring to the boil. Reduce the heat to low and simmer for 30 minutes. Remove from the heat and infuse for 10 minutes, then strain, reserving the liquid and seeds. Set aside 125 ml (4 fl oz/½ cup) liquid to make the black sesame glass.

Blend the seeds and remaining liquid, in two equal batches, in an upright blender until smooth. Pass through a fine sieve, discarding the solids.

Return both strained batches to the blender and, with the motor running, add the pomegranate molasses, spices, sugar, methylcellulose and xanthan gum. Add the lemon juice and remaining salt and blend until well combined. Transfer to a piping bag fitted with a 5 mm (¼ inch) plain nozzle, then place in the freezer and chill until 1–4°C (34–39°F). Once chilled, refrigerate until required.