Roll out the puff pastry to a 10-inch round. Add 50g of the butter to an 8-inch non-stick pan and allow it to melt. Tip in the peeled shallots and season with the salt and pepper.
Cook on top of the stove gently or in the oven until the shallots are cooked. Add the port to the hot pan and cook on the top of the stove until all of the port has evaporated. Allow the shallots to go cold.
Cover with the pastry and tuck the pastry down the sides of the pan to completely obscure the shallots from your vision. Prick a few times with the tip of a small knife. Cook in a pre-heated oven at 180°C/350°F/Gas Mark 4 for 20-25 minutes.
Whilst the tart is in the oven, make a vinaigrette by mixing the mustard, honey and vinegar together. Slowly add in the oil to ensure the vinaigrette comes together and emulsifies.
Remove the pan from the oven and allow to settle for 5 minutes before turning out on to a service dish. Crumble over the goat’s cheese and scatter round the toasted hazelnuts. Liberally spoon around the vinaigrette and scatter over the wild rocket. Serve immediately.