Heat the butter over medium heat in a medium sized skillet. Add the celery, carrot and shallot and saute for 6-8 minutes until softened. Add the freshly chopped sage, thyme and oregano and stir to combine. Cook for another 1 minute and then remove from heat and transfer to the fridge to cool.
In a large prep bowl combine the ground turkey, ground pork, panko bread crumbs, lemon zest, salt, pepper, heavy cream and eggs. Add the veggies and herbs once cooled. Carefully combine the mixture until evenly mixed.
Line a baking sheet with parchment paper.
Scoop out ⅓ cup sized scoops and roll into a ball. Transfer the balls to the lined baking sheet, the mixture should make about 20 large balls. Transfer the baking sheet into the freezer and freeze for 15 minutes.
Preheat an oven to 300°F.
Pour 2 inches of oil in a large heavy bottom dutch oven. 6-7 at a time, fry the meatballs just until browned and they hold their shape, about 3 minutes per batch over medium high heat. No need to flip as the oil should cover the meatballs. Transfer the meatballs to a clean braiser or baking dish as you remove them from the oil. They should be a little golden brown. Repeat until all meatballs have been fried.
Add enough stock to just barely cover the meatballs and place secure the top on the braiser. Transfer to the oven and bake for 30 minutes until cooked through.
Once the meatballs are done, use a slotted spoon and transfer the meatballs to a clean serving dish and set them aside.
Leaving braising liquid in the braiser for the time being.