Plenty for two:
Preheat the oven to 200 C. Peel the potato and squash and cut into approx. 3cm cubes. Chop the top off the onion but leave the bottom, hairy, end intact, peel off the papery outer layers then chop length-wise into 6-8 segments; the layers of each should hold together. Peel the beetroot and chop into about six pieces each (you might like to wear rubber gloves for this, unless you don't mind having pink-stained hands). Peel the carrot and chop into 3-4cm half-barrels. Heat the oil in a large roasting pan. Throw in all of the root vegetables and the onion, coat thoroughly with the hot oil and stir in the chilli flakes. Cook for about 15mins. Meanwhile, chop each pepper into inch squares. Once the root veg is almost cooked through, add the peppers and cook for a further 10 mins, turning the oven down to 190. Crumble the feta over the vegetables, season with pepper and blast again for another 5 mins, by which time the vegetables will be cooked through and just starting to tinge around the edges and the feta will be hot and dry. Serve in bowls.