In a medium bowl, whisk together the olive oil, soy sauce, red wine vinegar, Worcestershire sauce, and lemon juice until combined.

Add the minced garlic, brown sugar, paprika, onion powder, oregano, salt, and pepper. Whisk again until everything looks evenly blended.

Set aside about a quarter cup of the marinade separately for basting later.

Place the cubed steak into a large bowl or gallon-sized zip-top bag, then pour the marinade over it. Toss to coat and refrigerate for at least one hour, up to eight hours.

Cut the bell peppers, mushrooms, and red onion into sizes similar to your steak cubes.

Soak wooden skewers in water for 30 minutes if using wooden skewers.

Once the steak has marinated, remove it from the fridge and thread the steak and vegetables onto the skewers, alternating pieces.

Preheat the grill to high heat and cook the kabobs for about 8 to 10 minutes, turning every couple of minutes.

The meat should reach an internal temperature of about 135°F for medium-rare.

Transfer the finished kabobs to a platter and let them rest for about 5 minutes before serving.

Serve the kabobs hot, directly from the platter.