1. Preheat the oven to 160C fan-forced or 180C conventional. Line a baking tray with baking paper.
2. Toss the sweet potato in a little oil,season with salt and pepper and roast on the prepared tray for 30 minutes until tender. Set aside to cool.
3. Open out the pitas on a baking tray and bake for 10–15 minutes until crisp and lightly golden. Set aside to cool and crisp up.
4. To make the dressing,add 80 millilitres of oil,the orange zest and juice,lemon juice,cumin,chilli and olives to a medium bowl,season with pepper and combine. Add the orange slices and toss.
5. Arrange the sweet potato on a serving plate and follow with the sliced fennel,mayonnaise and chunks of tuna. Break up the pita,quickly toss through the dressing and tip over the salad. Garnish with the fennel fronds and serve.
Tips
1. Try adding some soft herbs,such as dill, mint or flat-leaf parsley.
2. Try this with roasted dutch carrots instead of sweet potato.
3. Lighten this by using yoghurt rather than mayonnaise.