Heat a frying pan and fry the sesame and cumin seeds for about a minute, until they start popping. Transfer them to a plate to cool.
Finely shred the cabbage into a bowl.
Chop the spring onions an add to the cabbage.
In a small bowl, whisk the tahini, water, garlic, lemon zest & juice with some freshly ground black pepper and salt. You should get a creamy dressing - if it’s too thick, add more water.
Pour the tahini dressing over the cabbage, then add most of the toasted seeds and toss until the cabbage is well coated.
Rest for a few minutes until the cabbage has slightly softened.
Just before serving, sprinkle the reserved seeds over the top.