I call it this because really you can use whatever you like as long as it's roastable. I'll detail what I used but you don't have to stick with that. Amounts are also variable - just think of what you would normally do for the number of people for which you are cooking
new potatoes, well scrubbed and cut into chunks
courgettes, onions, red or yellow pepper, small tomatoes, all prepped and chunked to same size as spuds
(I would also have used a few cloves of garlic if I'd had any)
some herbs from the garden (I used rosemary and thyme) or dried herbs
salt and pepper
some passata (not much) or make a tomatoey sauce from puree with water.
cooked meat - leftovers are perfect - or some pulses if you want to go vegetarian
In a roasting dish, add the vegetables, seasonings and herbs, pour over some oil (you don't need a lot) and mix to 'ensure maximum retention' (I've been reading Harry Potter!). I use my hands for this.
Cover with foil and bake in the oven (about 170 C) until all the veg is soft.
Remove the foil, turn up the heat, stir and pop back in so that they can start browning. It doesn't take long.
Add the cooked meat and the tomato passata/sauce and mix.
Pop back in the oven until the liquid is bubbling and everything is hot.
Sprinkle over grated cheddar and bake for around ten minutes more.
Serve immediately while bubbly hot.
With what I had, I went all Mediterranean-ish but you could use so many other veg, depending on availability. A good way to finish off those odds and ends. Also, really filling.