Choose a new cookbook worth up to £28 when you subscribe to our magazine.
Peel, then slice the onions into thin wedges. Thinly slice the garlic. Heat the butter and oil in a large wok or frying pan, tip in the onions and garlic and cook over a medium-high heat for 15 minutes, stirring every now and then until golden. Stir in the sugar and cook a minute or two longer. Season with salt and pepper. Preheat the oven to fan 200C/conventional 220C/gas 7.
Put the pizza bases on two oiled baking sheets. Spoon the onion mixture over the pizza bases. Now crumble over the feta and scatter with rosemary. Grind over some black pepper and drizzle with a little oil. Bake for 10 minutes and serve with a green salad.