Peel the sweet potato, and cut into chunks. Also dice the aubergine (eggplant). Toss the two vegetables in a dash of oil, and spread them out on a baking tray. Roast at 190°C (Gas Mark 5 / 375°F) for around 40 minutes, or until soft in the middle and crispy round the edges.
Meanwhile, heat a dash more oil in a large frying pan or wok. Add the onion and mushrooms, and cook over a medium heat for a few minutes, until slightly soft. Add the garlic and green beans, and cook for a few more minutes.
Add the Thai red curry paste, and mix to coat.
Pour in the coconut milk and vegetable stock, and add the Tenderstem broccoli and chickpeas, along with the roasted sweet potato and aubergine. Bring to a gentle simmer, and cook for another 5-10 minutes, until the vegetables are cooked to your liking.
Serve the Thai red curry with white rice, topped with fresh coriander (cilantro) if desired.