Heat 2 tbsp olive oil in a frying pan. Start dunking the aubergine slices in the beaten egg & frying them in the pan until they are lightly browned on both sides, approximately 4 minutes. Put aside the cooked aubergines on some paper towel to absorb the extra oil.
When you have cooked the aubergines, heat 1 tbsp olive oil in a frying pan. Add the minced meat & season with salt, pepper, paprika powder & garlic powder. Cook on high heat for 6 minutes or until it has browned.
Add the onions & peas. Cook for 7 minutes.
Add the concentrated tomato paste & the chopped tomatoes. Stir everything well & simmer for 30 minutes.
After the 30 minutes, turn the heat off & put it to the side.
Spray the casserole dish with baking spray & preheat oven at 180C.
Start by layering a layer of aubergines in a casserole dish. Layer a layer of tomato sauce, a layer of potato & keep going like this until you've used everything.
In a bowl mix the besciamella & the grated grana padano together.
Pour the besciamella mixture at the very end, on top of everything else.
Cook in the oven for 30-40 minutes.
Let it cool a bit before serving.