Preheat the oven to 425 degrees . Place a rack on a large baking sheet. Using a food processor, grind the stuffing cubes into crumbs, then transfer to a small bowl. Douse the stuffing with the stock to soften. (Don'tclean out the food processor; set aside.)
Drizzle the EVOO into a large bowl. Add the turkey; season with salt and pepper. Mix in the moist stuffing crumbs, the egg, onion, garlic, poultry seasoning, fennel seeds and crushed red pepper. Roll the meat into 1 1/2- to 2-inch balls. Arrange on the prepared baking sheet and roast until browned, about 15 minutes.
In a small bowl, combine all of the dipping sauce ingredients. Serve with the meatballs.
For the couscous: In a medium saucepan, bring the stock and butter to a boil. Stir in the couscous; season with salt and pepper. Cover the pan, turn off the heat and let stand for 5 minutes. Using the reserved food processor, chop the parsley. Fluff the couscous and stir in the parsley and walnuts.