In a large bowl, whisk together olive oil, balsamic vinegar, Worcestershire sauce, soy sauce, Dijon mustard, minced garlic, salt, and pepper.
Add cut steak to marinade.
Cover bowl with plastic wrap and store in the fridge for at least 2 hours before grilling.
After steak has marinated, slide alternating pieces of steak, onion, bell peppers and mushrooms onto skewers.
Heat grill to medium-high heat and grill for 8-10 minutes or until done.
