Tip the balsamic vinegar into a bowl and whisk with 1 tbsp oil and a pinch of salt and pepper. Add in the steaks and leave to marinate while you prepare the rest of the dish.
Peel and thinly slice the red onion. Halve and scoop out the seeds and white bits from the red pepper. Thinly slice. Pop in a bowl.
Using a veg peeler, peel ribbons off the courgette, turning it as you go till you get to the seeded core. Finely chop the seeded core and add to the bowl, but keep the ribbons separate. Drain and rinse the chickpeas.
Juice the orange. Finely chop half the rosemary leaves. Peel and grate the garlic. Pop them all into a separate bowl and whisk together.
Pour 1 tbsp oil into a pan. Add the pepper, onion and chopped courgette cores. Cook for 5 mins till slightly charred and softened. Add in the drained chickpeas along with the orange, garlic and rosemary mix. Cover and gently cook for 5 mins.
Warm a frying pan over a high heat. When hot, carefully place in the steaks, keeping any marinade in the bowl. Cook for 1 min each side for rare, 2 mins for medium and 3 for well done.
Remove the steaks from the pan and place in a baking dish. Pour the balsamic marinade into the hot pan. Allow to bubble up, then pour over the steaks. Cover with foil and leave to rest while you finish the caponata.
Add the courgette ribbons and olives to the veg. Cook for 1 min to just soften the courgette. Taste the caponata and add more salt and pepper if it needs it. Spoon the caponata onto two warmed plates. Top with the balsamic steak and juices from the dish.