Preheat oven to 400.
Place turkey in a bowl and make a well in the middle of it. Add the spinach, all but 3 tablespoons of the onion, garlic, 1 large egg, 1/4 cup heavy cream, ground pistachios, grated Parmesan and a pinch of kosher salt and pepper. Mix well. Form into 12 large balls and drizzle with extra-virgin olive oil. Arrange on a nonstick cookie sheet and roast for 30 minutes, or until cooked through.