Rinse the beef and pat dry with a paper towel.
Place all the ingredients in a large sealable plastic bag.
Seal the bag, removing some of the air.
Mix to coat the beef with the marinade.
Place in the fridge for 1 hour, up to overnight.
Remove from the fridge 15 minutes before cooking.
Heat grill to 400 degrees F.
For medium-rare meat, grill for around 4 to 5 minutes on each side. Or until 135 degrees F.
For medium, grill it for 5 to 7 minutes each side. or until 140 degrees F.
For medium-well beef, grill it for 8 to 10 minutes each side. Or until 150 degrees Fahrenheit.
Place the cooked beef on a plate and cover with foil.
Let rest until ready to slice.
Slice against the grain into thin strips.
Serve as tacos on top of warm tortillas, top with onion, cilantro, and salsa.