Pre heat oven to 215C / 420F
Wash, scrub and cut the ends off the sweet potatoes. Cut into 2.5cm / 1 inch cubes
In a large bowl, toss the cubed sweet potatoes with 2 tbsp of the olive oil, half the herbs and the salt. Stir until coated.
Arrange potatoes in a single layer over two baking trays, making sure to not to overcrowd. Bake for 20 min, stirring halfway through.
While the sweet potatoes are baking, core and chop the apples into 2.5cm / 1 inch cubes. Add to a large bowl and toss in the remaining oil and herbs.
After 20 minutes, remove the sweet potatoes from oven, add the apples and stir to combine.
Return to the oven and bake for a further 15 minutes, stirring halfway through.
Allow to cool for a couple of minutes before removing from the tray.