Measure and prepare all your ingredients.
This will help streamline the process.
In a large bowl, combine soy sauce, olive oil, brown sugar, and balsamic vinegar.
Stir until the sugar dissolves completely.
Add garlic, black pepper, Italian seasoning, and Worcestershire sauce to the mix.
Give it a good whisk to blend everything evenly.
If you like a bit of heat, stir in the red pepper.
Or, skip it if you prefer a milder flavor.
Place your steak in a resealable bag or shallow dish.
Pour the marinade over the steak ensuring it’s completely coated.