- Preheat the oven to 200°C/ gas 6. Add 1.1⁄2 tbsp olive oil to a bowl with the onions, peppers and courgettes. Mix well, spread out on a baking tray and roast for 25-30 minutes.
- Meanwhile, add the boiling water to a large pan and gradually mix in the polenta, stirring with a wooden spoon for around 5 minutes. Then, transfer into a lightly oiled 2lb loaf tin (approx 22cm x 11cm), and flatten the top with back of a spoon. Set aside for 5 minutes.
- Add the tinned tomatoes, garlic, oregano and chilli flakes to a pan, stir together and simmer gently for 5 minutes.
- Turn the polenta out onto a chopping board and cut into 1.1/2-cm thick slices, then cook on a hot griddle pan or under the grill for around 3-4 minutes on each side until lightly golden.
- To serve, drizzle a slice of the polenta with a spoonful of the tomato and herb sauce, scatter some of the roasted vegetables on the top and finish with a few fresh basil leaves. Add a small handful of grated cheese, if desired.
- Use any vegetables of your choice to create a variation of this dish. Aubergines and mushrooms work well.
- Freezing instructions: Freeze the polenta and vegetables separately. Then defrost in the fridge or microwave and reheat until piping hot throughout.