Slice meat into strips about ⅜" thick to ensure total saturation while it is marinating.
In a container, combine soy sauce, worchestershire sauce, meat tenderizer, seasoned salt and black pepper. Marinate overnight. Season strips with garlic and onion powder. Lay strips on oven rack. Cook for 6 - 8 hours at 150°F. Store in airtight container. Jerky will keep up to 2 yrs.
Recipe by Old Fashioned Families at https://www.oldfashionedfamilies.com/jerky/