Slice the beef thinly, about 1/8 to 1/4 inch thick. Freeze it first if you struggle with precise cuts — it firms up the meat for clean slices.
In a bowl, mix soy sauce, Worcestershire, brown sugar, paprika, garlic powder, onion powder, red pepper flakes, salt, and pepper. Whisk until it looks glossy and confident.
Toss the beef slices in the marinade until every piece is coated. Cover and refrigerate for at least 4 hours, preferably overnight for maximum flavor.
Preheat your oven to 170–175°F (or use a dehydrator if you’re fancy). Line racks with foil and place strips on them, leaving space to breathe.
Dry the beef for 4–6 hours, flipping halfway. It should be dry and springy, not crumbly or mushy. Time varies with thickness and your oven’s mood.
Let it cool completely, then store in an airtight container. It’ll still taste great after a week if you’re not hoarding it like a dragon.