Prepare the Beef: Begin by placing the beef in the freezer for about 1-2 hours until it's partially frozen. This will make slicing it into thin strips much easier. Once firm, remove the beef and slice it against the grain into thin strips, around ¼ inch thick.

Make the Marinade: In a large mixing bowl, combine soy sauce, teriyaki sauce, brown sugar, honey, garlic powder, onion powder, ground ginger, black pepper, red pepper flakes (if using), and sesame oil. Whisk the ingredients together until the brown sugar is dissolved and the mixture is well combined.

Marinate the Beef: Add the beef strips to the marinade, ensuring each piece is thoroughly coated. Cover the bowl with plastic wrap or transfer the mixture to a resealable plastic bag. Refrigerate for at least 4 hours, or preferably overnight, to allow the beef to absorb the flavors.

Prepare for Drying: Preheat your oven to 175°F (80°C). If you have a dehydrator, you can use that as well. Line a baking sheet with aluminum foil for easy cleanup. Place a wire rack on top of the baking sheet to allow for air circulation.

Arrange the Beef: Remove the beef from the marinade and pat it dry with paper towels to eliminate excess moisture. This step helps improve the drying process. Lay the beef strips in a single layer on the wire rack, making sure the pieces do not touch each other.

Dry the Jerky: Place the baking sheet with the wire rack in the preheated oven. Leave the oven door slightly ajar to allow moisture to escape (you can use a wooden spoon to prop it open). Dry the beef for 4-6 hours, flipping the strips halfway through, until the jerky is firm but still slightly pliable (it shouldn't be brittle).

Cool and Store: Once done, remove the jerky from the oven and let it cool completely on the rack. Store the cooled jerky in an airtight container or zip-lock bag. It can be kept at room temperature for a couple of weeks or refrigerated for longer shelf life.