Heat oven to 200C/180C fan/gas 6. Layer up half the potato, tomato and aubergine in a baking dish, scattering with garlic, oregano and olives, and drizzling with oil and seasoning as you go.
Scatter over the feta, then repeat the layers until all the ingredients are used up. Finish with potatoes and a little oil.
Bake for 50 mins or until the veg are tender (cover with foil if they’re getting too brown). Top with the lamb steaks, rubbing with a little more oil and seasoning. Bake for 15-20 mins more until the lamb is cooked. Allow to rest and cool a bit before scattering with oregano and serving with crusty bread.