Combine all ingredients for the marinade in a large bowl, then add the steak strips. Cover with aluminum foil and marinate for 30 minutes at room temperature.
2 tablespoons vegetable oil, 3 cloves garlic, 1 onion, 1 tablespoon lemon juice, ½ tablespoon Worcestershire sauce, ½ teaspoon beef bouillon granules, 1 teaspoon dried thyme, 1½ teaspoons dried oregano, ¼ teaspoon crushed red pepper flakes, kosher salt and freshly ground black pepper, 1½ pounds sirloin steak