Heat some olive oil in a casserole dish, then add the butternut and cook on high for 10 min to
brown the edges;
remove with a slotted spoon and set aside.
Add some more olive oil, then brown the mushrooms for 6-8 min, stirring occasionally.
Set aside with the butternut.
Top up with oil again if needed and add the onion and cook until golden brown (8-12 minutes);
make the vegetable stock.
Add the garlic, sage and pearl barley to the pot and stir, then add the stock, bring to a boil
and cook for 10 min.
Reduce to a simmer, add the butternut and mushrooms and cook for 40 minutes partially covered,
stirring occasionally.
Check the pearl barley and cook for a further 5-10 min if not done yet (you can also add water
if it is drying out).
Mix through the parmiggiano and serve topped with olive oil, sage leaves and parmiggiano.