Halve the butternut squash lengthwise and remove the seeds with a spoon. Brush each half with 1 tablespoon of olive oil. Place the halves with the cut side down on a baking tray lined with baking paper . Roast in the middle of the oven for approx. 35 minutes until soft and cooked.
Meanwhile peel the sweet potatoes. Cut into slices of approx. 5 mm thick. Or use a grater or mandolin to make thin slices. Cut the courgettes and tomatoes into thin slices.
Grease the oven dish with butter. Make a layer on the base of dish with half the sweet potato. Season with ½ tablespoon of the Italian herbs . Season with salt and pepper. Divide half of the courgettes over this layer. Now make a layer of the tomatoes. Season with ½ tablespoon of the Italian herbs . Season with salt and pepper. Finish by making another layer of courgettes, followed by a layer of sweet potato. Season with ½ tablespoon of the Italian herbs . Season with salt and pepper. Drizzle with 1 tablespoon of olive oil. Cover the dish with aluminium foil. Bake in the oven for 30 minutes (with the butternut squash).
Remove the squash from the oven and leave to cool. Remove the skin. Purée the flesh until smooth. Add the butter and the egg. Season with salt and pepper.
Remove the oven dish with the vegetables from the oven after 30 minutes. Pour off any excess liquid. Spread the squash purée over the top. Return to the oven for another 30 minutes.
Tip: Crumble 200 grams of feta over the squash purée for an extra salty flavour.
