Peel and thickly slice the red onion. Halve the pepper. Scoop out the seeds and white bits. Thinly slice. Trim the carrot and cut into 3cm-thick slices. Chop the sweet potato into 4cm-thick slices.
Peel and grate the ginger. Zest the orange (save the orange for later). Cut the pork stir-fry strips in half.
Warm a large pan over a medium heat. Add 1 tbsp oil to the hot pan. Add the pork strips and fry for 4-5 mins till golden on both sides. Transfer from the pan to a bowl using a slotted spoon.
Keeping the pan on the heat, add the onion and pepper. You shouldn’t need any more oil. Cook for 3 mins till the onion is just beginning to soften. Turn the heat to low.
Tip the pork back into the pan along with any resting juices. Add 1 tsp jerk spice and stir together. Add the carrots and sweet potato to the pan and stir to coat them in the spices. Rinse the pearl barley under cold water, then add to the pan.
Add the grated ginger and orange zest to the pan. Pour in 500 ml boiling water. Spoon in 1 tbsp honey. Stir together. Cover and simmer over a medium heat for 25 mins. The barley and veg should be tender.
While the pork is cooking, cut the zested orange into wedges. Taste the pork. Add salt and pepper if you like, and more jerk spice if you like things hot. Serve the pork in warm bowls with the orange wedges to squeeze over.