Place the pepper halves, skin side up, on a baking tray and place under a hot grill.  Cook for 10—12 minutes, until completely blackened. Meanwhile, toast the cumin seeds in a dry pan for 2-3 minutes.  Remove from the heat. Transfer the charred peppers to a bowl and cover with cling-film.  Leave until cool enough to handle.

Remove the blackened skin of the peppers and place the flesh in a food processor with the cumin seeds, black chia seeds, the crushed garlic and harissa paste. Blend until smooth, and then season to taste.

Serve sprinkled with the white chia seeds, with vegetable crudités for dipping.