In a mixing bowl, combine soy sauce, Worcestershire sauce, liquid smoke, black pepper, garlic powder, and onion powder. Stir to mix well.
Add the sliced yak meat to the marinade, ensuring each piece is well coated. Cover and refrigerate for at least 4 hours, preferably overnight.
Preheat your oven to 175°F (80°C) or use a dehydrator set to the meat setting.
Place marinated yak slices on a baking rack over a baking sheet, or in dehydrator trays, making sure they do not overlap.
Dry in the oven or dehydrator until the jerky is dry and leathery, typically 4-6 hours depending on thickness.
Allow to cool completely before storing in an airtight container.