Preheat your oven to 200°F (93°C) and line baking sheets with parchment paper.

Wash the sweet potatoes thoroughly and slice them into thin strips using a mandoline slicer or a sharp knife. Aim for slices about 1/8 inch thick.

In a mixing bowl, combine the vegetable broth, nutritional yeast, soy sauce or tamari, and liquid smoke (if using). Stir well to create the marinade.

Place the sweet potato slices into the marinade, ensuring they are evenly coated. Let them marinate for at least 10 minutes or up to an hour for more flavor.

Arrange the marinated sweet potato slices in a single layer on the prepared baking sheets.

Place the baking sheets in the preheated oven and bake for 3-4 hours, or until the sweet potato slices are dry and chewy, resembling jerky. You can flip the slices halfway through for even drying.

Once the sweet potato jerky is cooked, remove it from the oven and transfer the slices to a cooling rack. Let them cool completely before serving.

Store the sweet potato jerky in an airtight container in the refrigerator for up to one week. Alternatively, you can freeze them for longer shelf life.