1 Preheat the oven to 220°C (200°C in a fan oven), 425°F, gas 7 and brush the quiche tin with oil.
2 Spread out the pastry and cut to the size of the tin. Line the tin with the pastry, forming a lip around the edge. Prick the base all over with a fork.
3 Arrange around 150 g of the salmon evenly over the base.
4 Whisk together the milk, crème fraîche and eggs. Stir in the leek, chives and dill, and season with ground black pepper, nutmeg and a little salt. Pour the mixture over the salmon and sprinkle with cheese. Bake in the oven for around 40 minutes, until golden brown.
5 For the avocado mousse, mash the avocado flesh well with a fork. Mix through the tomatoes and coriander and season to taste with a dash of lemon juice, salt and chilli powder.
6 Take the quiche out of the oven and allow to cool slightly. Form the avocado mixture into small quenelles and place around the edge of the quiche. Place the remaining smoked salmon next to the avocado and garnish with salmon roe and coriander before serving.