In a medium mixing bowl, whisk together the barbecue sauce, steak sauce, Worcestershire sauce, mustard, red wine vinegar, soy sauce, hot chili powder, red pepper flakes, dried marjoram, black pepper, and salt until well combined.

Place the beef steaks in a sealable plastic bag or shallow dish.

Pour the marinade over the steaks, ensuring they are evenly coated.

Seal the bag or cover the dish with plastic wrap and refrigerate for at least 4 hours, or overnight for best results.

When ready to cook, preheat your grill or grill pan to medium-high heat.

Remove the steaks from the marinade and discard any excess marinade.

Grill the steaks for about 4-6 minutes per side, or until desired doneness is reached, flipping only once.

Remove the steaks from the grill and let them rest for a few minutes before serving.