Preheat the oven to 180°C.
Peel and cut the squash into 3cm cubes. Scatter them into a roasting tin.
Peel then cut the onions into wedges. Peel the garlic and cut them into thin slices. Tuck these between the squash cubes. Scatter the chilli flakes and rosemary leaves on top, season with salt & pepper and drizzle with oil & vinegar.
Combine well, then bake for 15 minutes until the squash starts to caramelize. Add the tinned cherry tomatoes, mix well and cook for another 15-20 minutes until golden.
Serve warm.
