Step #1 Heat oven to 190°C
Heat 1 tbsp oil In a large-ish pan, then fry mushrooms for 4-5 mins, stirring every once in awhile, until lightly browned.
Step #2 Remove with a slotted spoon, then set aside.
Step #3 Add remaining oil to the pan, onion & garlic over a low heat, stirring every once in awhile, then fry the celery, for 5-6 mins Add wine, stock & thyme & bring to the boil.
Step #4 Simmer for 30 mins.
Step #5 Add the port & redcurrant jelly.
Step #6 Bring back to the boil, then boil for 10 mins until reduced by half & thick & syrupy.
Step #7 Spice up to taste, discard the thyme & stir in the the mushrooms.
Step #8 Simmer for 5 mins.
Step #9 Meanwhile, pull the tops off the brioche & reserve, then pick out dough from the centre to leave a thick shell.
Step #10 (Process remaining dough to make breadcrumbs, then freeze for future use.
Step #11 ) Place rolls on a baking sheet, then bake for 5-7 mins until hot & crisp.
Step #12 Spoon the mushroom mixture into the brioche rolls, then garnish with the flat-leaf parsley.
Step #13 Serve as soon as possible with any remaining gravy, potato wedges & green beans.