Peel the sweet potato if you like. I don't because we like the skin. Mix with the olive oil and season, then cook in an air fryer or on a tray in a hot oven for 30-40 minutes or until cooked and starting to brown. Turn them over halfway through cooking.
Peel the pineapple, remove the core then cut it into pieces then blitz them in a food processor until finely chopped. Add remaining ingredients and mix briefly. Tip into a saucepan, bring to the boil, then simmer for 5-10 minutes to reduce a bit.
When the sweet potato is cooked arrange it in a baking dish in one layer, slightly overlapping. Drizzle with some of the sauce - you may not need it all - then put the dish in a hot oven for 20 minutes, or until the dressing turns starts to colour and become a bit sticky. If your air fryer is big enough you can do this stage in there, but the sweet potato needs to be in a single layer, not too crowded.
Arrange sweet potato on a bed of greens, lightly dressed with your favourite salad dressing. Serve hot, or at room temperature.