Three-cheese polenta triangles with caramelised onions

To make three-cheese polenta, brush a square 23cm (base measurement) cake pan with oil to lightly grease. Line base with non-stick baking paper, allowing it to overhang. Bring stock and water to the boil in a large heavy-based saucepan over high heat. Gradually add polenta in a thin steady stream, whisking constantly until incorporated. Reduce heat to low and simmer, stirring constantly with a wooden spoon, for 10 minutes or until mixture thickens and polenta is soft. Remove from heat. Add blue cheese, parmesan and mascarpone, and stir until well combined. Taste and season with salt and pepper. Pour into prepared pan and use the back of a spoon to smooth the surface. Set aside for 15 minutes to cool slightly. Cover with plastic wrap and place in the fridge for 3 hours to set.

Meanwhile, melt the butter in a large frying pan over medium-low heat until foaming. Add onion and garlic and cook, stirring occasionally, for 20 minutes or until onion is soft and golden brown. Add sugar and cook, stirring, for 5 minutes or until sugar dissolves and begins to caramelise. Add vinegar and thyme and cook, stirring, for 5 minutes or until mixture thickens. Taste and season with salt and pepper. Remove from heat.

Turn the polenta onto a clean work surface and cut into quarters. Cut each quarter in half diagonally. Heat oil in a large non-stick frying pan over medium-high heat. Add 2 polenta wedges and cook for 2 minutes each side or until golden brown and heated through. Transfer to a plate and cover with foil to keep warm. Repeat in 3 more batches with the remaining polenta wedges.

Arrange polenta on plates. Top with caramelised onion and sprinkle with feta and thyme. Serve immediately.