1: Preheat the oven to 360°F (180°C). Spread 100 g sesame seeds over a sheet of cooking parchment laid on a baking sheet. Toast in the oven for 5 minutes. Leave to cool. Keep the paper; we'll be using it again in stage 8.
2: Put into a mixer bowl: 250 g flour, 120 g butter, 100 g caster sugar, 50 g egg, 2 pinches salt, 1 tablespoon sesame oil and 2 g baking powder. Add the cooled, toasted sesame seeds.
3: Start the mixer...
4: ...and knead until evenly mixed.
5: Flatten the dough out into disc, wrap in plastic film and refrigerate for at least 2 hours. All this can be done the day before and left overnight in the fridge.
6: Preheat the oven to 360°F (180°C). Roll out the really cold dough with a rolling pin, not too thinly, about 1/4 inch (1/2 cm) thick.
7: Cut into strips just over an inch (3 cm) wide.
8: Cut across the strips to create the biscuits, about 2 inches (5 cm) long here. Sit these on a sheet of cooking parchment laid on a baking sheet. Tip: reuse the paper from toasting the sesame seeds in Step 1.