Sweet potato pizza: Slice assorted sweet potatoes and toss in egg white to coat. Season and arrange in a circle, overlapping each slice, on a non-stick tray. Brush with melted butter and bake at 170°C for 20–25 minutes until crisp and golden. Top with your favourite ingredients, like kale leaves, fresh cheese sauce and sliced chorizo. Bake again to heat through and serve with grilled cherry tomatoes.