Add sesame seeds and cook for 1 minute, shaking pan frequently, until light golden and toasted. Transfer to a mortar and pestle.
Re-heat pan and toast cumin, coriander and chilli for 30 seconds, shaking pan frequently, until fragrant. Transfer to mortar and pestle.
Pound seeds and spices together until coarsely crushed. Add salt and stir gently with a spoon to combine. Set aside to cool.
Line a large bamboo steamer or 4 individual steamers with non-stick baking paper and puncture the paper with several holes to allow the steam to pass through. Spread peas evenly over prepared steamer and cover. Set over a wok of simmering water and allow to steam for 2-3 minutes until bright green and just tender.