Preheat the oven to 180°C.
Finely slice the celery and peel the shallots.
In a heavy-based casserole dish, half of the butter and gently sauté the celery an shallots for a couple of minutes, then transfer to a plate.
Add half of the remaining butter to the pan and fry the game bits for about 2-3 minutes until lightly browned. Return the celery and shallots to the pan and stir for a few seconds.
Add the cider and let it bubble for 1 minute. Add 2 of the thyme sprigs and season to taste. Put the lid on and cook in the oven for 40 minutes or until the game is tender.
Core and cut the apples into wedges.
Heat a frying pan, add the remaining butter and fry the apple for 2-3 minutes until golden and starts to caramelise. Remove from the pan and keep warm.
Add the crème fraîche to the casserole, stir to combine (if used).
Serve with the caramelised apple and some thyme leaves scattered on top.