Start by slicing the beef into thin strips (about ⅛ to ¼ inch thick). For easier slicing, partially freeze the beef for 1-2 hours before cutting.

In a mixing bowl, combine the soy sauce, Worcestershire sauce, brown sugar, garlic powder, onion powder, black pepper, and red pepper flakes if using. Mix well to create the marinade.

Place the beef strips in a zip-top plastic bag and pour the marinade over the meat. Seal the bag and massage the marinade into the beef to ensure every piece is coated. Refrigerate for at least 3 hours, preferably overnight for better flavor.

If using a dehydrator, arrange the marinated beef strips on the dehydrator trays in a single layer, leaving space between the pieces. Set the dehydrator to 155°F (68°C) and dry for about 4 hours, or until the jerky is dry but still slightly pliable.

If using an oven, preheat the oven to the lowest setting (usually around 160°F/70°C). Place a wire rack on a baking sheet and lay the beef strips on the rack in a single layer. Prop the oven door open slightly to allow moisture to escape. Bake for 4-6 hours, or until the jerky is dry.

Once done, let the jerky cool completely before storing it in an airtight container or a zip-top bag.

Store the jerky in the refrigerator to prolong its shelf life.

To test for doneness, the jerky should bend and crack, not break.