For the vegetable stack, rub the courgette and aubergine slices with the olive oil and season with salt and freshly ground black pepper. Heat a griddle pan until hot and griddle the courgette and aubergine slices for 2-3 minutes on each side, or until softened and lightly charred. Set aside and keep warm.
For the chargrilled polenta, place the polenta and stock into a small saucepan. Add the chilli flakes, rosemary and seasoning and bring to the boil. Reduce the heat and simmer for 2-3 minutes, or until all the stock has been absorbed and the polenta is no longer grainy.
Lightly oil a small roasting tin and pour in the polenta. Allow to cool, then place into the fridge to chill and set. When set, cut the polenta into three equally sized squares.
Rub the squares with olive oil, heat a griddle pan and griddle the polenta squares for 1-2 minutes on each side, until lightly charred.
For the sauce vierge, place all the sauce vierge ingredients into a bowl and mix well.
To serve, place one chargrilled polenta square onto a serving plate and top with the grilled courgette slices. Place another layer of polenta on top, then the aubergine slices, followed by the final square of polenta. Pour the sauce vierge around the plate.