Place a baking sheet in the oven and heat to 200`c. Brush the filo pastry sheets with 2 tablespoons of the olive oil and use to line a 23cm round, loose-bottomed tart tin. Layer the sheets at different angles so that the base and sides are well covered, and allow the pastry to drape over the sides. Place the remaining olive oil in a pan and sauté together the spring onions, garlic and season well with salt and pepper. Remove off the heat. In a bowl, whisk together the mustard, ricotta cheese and eggs till smooth and season well. Scatter ½ of the cooked spring onion mix and half the broken goat’s cheese over the pastry base, pour over the egg mix and top with the remaining cheese and spring onions. Sprinkle over the hazelnuts, then fold in the overhanging pastry and brush with the remaining oil. Bake the tart on the heated baking sheet for 35-40 minutes until the filling is set and the pastry is golden. Allow to settle for 10 minutes before carefully removing from the tin and serving.