Step 1
Preheat oven to 180°C. Heat a large frying pan over high heat. Add mince and cook, stirring with a wooden spoon to break up lumps, for 5 mins or until the mince changes colour. Add onion and cook for 10 mins or until onion softens.
Step 2
Add the tomato paste and cook, stirring, for 5 mins or until well combined. Add the tomato and cook, stirring occasionally, for 15 mins or until the mixture thickens. Season.
Step 3
Meanwhile, spray a large frying pan with olive oil spray and heat over medium heat. Cook potato, in batches, for 2-3 mins each side or until golden and tender. Transfer to a plate. Spray the eggplant with olive oil spray and cook in the pan, in batches, for 1-2 mins each side or until golden and tender.
Step 4
Spread half the mince mixture over the base of a 6-cup (1.5L) ovenproof dish. Top with half the potato, eggplant and cheese sauce. Repeat layering with the remaining mince mixture, potato, eggplant and cheese sauce. Sprinkle with breadcrumbs and spray with olive oil spray. Bake for 40 mins or until golden brown. Cut into slices to serve.
Get ahead: Assemble the moussaka, then cover with foil and freeze. Thaw in the fridge overnight before baking until heated through