Pre-heat oven to 200°C.
Cut eggplant into 12 slices, each slice approx. ½ - 1cm thickness. Place slices into a colander, sprinkle eggplant surfaces generously with salt; stand 20min. Rinse eggplant of salt and juices under cold water, pat dry with paper towel.
Place eggplant, in a single layer, on an oven tray sprayed with oil. Roast 15min; until just tender. Meanwhile, slice onion into 12 thin slices, and each tomato into 6 slices.
Onto a baking tray lined with paper, stack a slice of eggplant, a slice of onion, then a slice of tomato. Top this with another slice of eggplant, then onion, and then tomato, brushing each layer with a little oil whilst “stacking”. Top with a slice of cheese. Repeat until all vegetables and cheese has been used; you will have 6 stacks.
Bake 15min; cheese will melt and be golden in spots. Serve warm.
For a complete meal serve stacks with a side of hot tomato passata and a green salad.
Try topping stacks with different low protein cheeses to vary the taste; grated parmesan and mozzarella also work well.