To make the dukkah
Add all the ingredients (excluding salt) into a blender and blend for around 1 minute until it’s choppy, chunky and generally mixed. Add salt or chilli flakes if you fancy.
To make the sun-dried tomato hummus
Add lemon juice, tahini and olive oil of a blender or food processor. Blend until smooth, about 40 seconds. Add sundried tomatoes, garlic, cumin, salt and chickpeas. Blend until smooth.
To make the sweet potatoes and assemble
Roast the sweet potatoes at 180°C/350°F/gas mark 4 for about an hour or until completely tender.
Dice the avocados and squeeze over the juice of half a lime.
Halve the sweet potatoes and top them with a dollop of hummus, the avocado, a crumbling of tofu or feta cheese and a sprinkling of dukkah.