Preheat oven to 425° F.
Place 6 individual serving sized oven-proof casserole dishes on a baking sheet. Divide braised rabbit pie filling between the dishes, leaving 1 cm clearance from the top.
Brush the edge of all 6 pieces of puff pastry with the whisked egg wash and place this side over all of the filled casserole dishes, pinching with fingers to seal around the dishes.
Brush the top of the sealed puff pastry with egg wash and place 2 whole sage leaves on each.
Bake until pastry is golden and has risen, approximately 15 to 20 minutes.
While the pot pies are baking, assemble the garnish by tossing the kale and the frisee with the lemon juice and truffle oil. Season to taste.
Once the pies are ready, remove from the oven and transfer each to liner plates, top with the salad and serve immediately.
Preheat oven to 325°F.
Preheat a heavy bottomed oven proof braising pot (like a Dutch oven), on medium high heat.
Season the outside of the whole rabbit with salt and pepper, add 3 tbsp oil into the pot and begin searing 1 side of the whole rabbit until an even brown crust develops. Flip to the other side and repeat.
Remove the whole rabbit from the pot and set aside. With the pot still on medium heat, add sliced onions and sweat for 5 to 7 minutes, or until the onions soften and have taken on light colour.
Deglaze with white wine being sure to scrape up all brown bits from the bottom of the pot, and reduce this liquid by half.
Add in chicken stock, thyme sprigs, 1 bunch sage and the seared rabbit. Bring to a simmer, cover with lid and transfer to preheated oven and continue to braise until the rabbit meat just starts to pull away from the bones (approximately 1 hour).
Remove the pot from oven and take out the braised rabbit, picking away the meat from the bones, strain off the braising liquid over a bowl and set aside.
In a medium pot over medium heat, add remaining oil, sweat the carrot, parsnip, diced white onion, celery, garlic, chopped thyme and chopped sage until they have just started to soften, remove from the pot and set aside.
In the same pot, make a roux by whisking together butter and flour, and cook for 2 to 4 minutes. Add in the reserved liquid from the braised rabbit, 1 cup at a time, while still whisking until fully combined.
Bring to a simmer and allow to cook for 20 minutes.
Add in the rabbit meat and cooked vegetables, adjust seasoning as necessary and set aside until ready to bake and assemble.