In a bowl or resealable plastic bag, combine the soy sauce, olive oil, brown sugar, Worcestershire sauce, Dijon mustard, minced garlic, salt, and pepper
Place the steak into the bag or bowl and coat well with the marinade
Let the steak marinate in the fridge anywhere from 30 minutes to 24 hours
Once ready to cook, remove the steak from the marinade and let it come to room temperature
If grilling: Make sure you preheat the grill to medium-high. Brush the grates with oil or spray them with cooking spray. Grill the steak for about 5 minutes per side (or until the desired doneness is reached)
For pan-searing: heat a large skillet over medium high heat. Add a drizzle of olive oil or spray with cooking spray. Cook the steak for about 5 minutes per side
Let the steak rest briefly before slicing and serving