For the potato rösti, place the grated potato into a clean tea towel and squeeze out the excess moisture.
Heat the olive oil in a small frying pan and add the grated potato. Season with salt and freshly ground black pepper and fry for 3-4 minutes, then flip over using a fish slice and fry for 2-3 minutes on the other side, or until golden-brown on both sides.
For the herb salad, place the herbs into a bowl with the lemon juice and the olive oil and season with salt and freshly ground black pepper. Stir well to coat the herbs.
To serve, place the rösti onto a serving plate and top with the herb salad and the fried egg. Scatter the Brie around the plate and garnish with chives.