For the celeriac velouté:
Heat the oil in a heavy-bottomed pan and sweat the onions over a medium heat for 2-3 minutes until soft, but before they start to colour. Add the celeriac and sweat gently over a medium heat. If you place a lid over the pan for 3-4 minutes, it will create a steam to give you a more flavoursome result.
Add the lemon juice and the chopped apple, then cover the celeriac with the chicken stock and milk. Bring to the boil and heat for 15-20 minutes. If it starts to reduce down too much, add more milk and stock as required. Season with salt and pepper. Once the celeriac is soft, put it into a blender and mix until smooth.
For the venison burger:
You can buy quality minced venison from your local butcher or farmer’s market. If you haven’t bought minced venison, then mince it, and add the apricots and mix. Add the egg, pork fat, cream and breadcrumbs and mix together, seasoning with salt and pepper. To test the seasoning of the burger, roll a small amount into a mini burger, pan fry and taste.
When satisfied with the seasoning, form the meat into four thick burgers and rub each with a little oil. Heat a heavy-bottomed pan over a medium heat. When it begins to smoke, add the burgers and cook for 3-4 minutes on each side or until they are cooked to your taste.
Gently fry the bacon in a heavy-bottomed frying pan and chop into small pieces. Pour the celeriac velouté into deep bowls and place the venison burger in the centre. Garnish with the crispy bacon, croutons, celery leaves and the chervil if you wish, and finish with a drizzle of rapeseed oil.