Line the side of the tin with the aubergine slices, overlapping them slightly and letting them hang over the top, then cover the gap left in the centre with more overlapping slices. Loosely fill the tin with the bucatini mixture (do not compact the pasta or the dish will lose its lightness), fold the overlapping aubergine slices over the pasta and cover the centre with the rest of the aubergine slices. Bake for 30 to 40 minutes. Leave to cool then flip the timbale on a serving platter. Slice and serve, garnished with fresh basil leaves.