Bring a large pot of salted water to a boil. Cook the collards for 3 to 4 minutes until soft and pliable. Drain and set aside. In a large bowl, mix together pork, salt, cumin, chili flakes, onion powder, garlic powder, oregano, and nutmeg in a bowl. Divide into 4 sections to form oblong patties. Wrap each patty in 4 collard leaves. Place patties seam side down in the baking dish and add enough stock to reach 1/4 of the way up the stuffed greens. Cover with heavy-duty aluminum foil and bake until pork is cooked through, about 35 minutes.