Cook the sweet potato slices in boiling water for 6–8 minutes or until tender. Drain and leave to cool.
Poach the chicken breasts in simmering water (use the water from the sweet potatoes, if you like) for 4–6 minutes or until cooked through. Drain and leave to cool, then cut into 1 cm slices.
Put the chicken and sweet potato slices in a bowl and sprinkle with the cinnamon and cumin.
To make the salsa, combine the pineapple, red onion, red capsicum, mint, chilli powder, cinnamon, cumin and lime juice in a mixing bowl.
Mix the dressing ingredients in a large shallow salad bowl. Add the salad leaves and toss to coat with the dressing. Arrange the chicken and sweet potato slices, the cucumber slices and tomato wedges on top of the leaves, then scatter with the chopped coriander leaves, sunflower seeds and spring onions. Serve with the salsa.