1. Set the oven to 185 degrees.
2. Put the sugar, vinegar, mixed spice, butter and grain mustard into a pan.
3. Quarter and slice the apples into 1cm pieces, then add to the pan. Cook on a high heat for five minutes until the apples soften but don’t let them get mushy.
4. Fold the shredded duck meat through the apples, season and allow to cool.
5. Unfold the pastry, then put the parchment from the packet on to a baking tray and lay the pastry on top.
6. Egg-wash the pastry, then spread the filling on the base, leaving a 3cm lip all around. Turn the edge of the pastry in on itself to form a lip, then egg-wash the edge again.
7. Bake for 20 minutes, then remove from the oven.
8. Brush the tart with the redcurrant jelly, then scatter over the sesame seeds and redcurrants, and return it to the oven for five minutes.
9. Eat warm with a watercress salad dressed with a little nut oil as a perfect accompaniment.