Whisk all of the marinade ingredients together in a bowl. Marinate the flank steak for 3-4 hours minimum (or overnight). Heat a grill over medium high heat. Remove the flank steak and discard any remaining marinade. Cook the steak for 7 minutes each side for medium. If you prefer medium rare steak, do 6 minutes. For medium well, do 8 minutes. Let the steak rest for 5 minutes. Slice and serve in bowls or tacos! Roasted Veggies (if using) Preheat your oven to Toss the roasted veggie ingredients together in a bowl. Spread the vegetables out on a parchment paper-lined baking sheet. Bake for 20-25 minutes until the peppers, onions, and mushrooms are tender and starting to get brown and crispy. Serve with the carne asada, cauliflower rice, and other desired toppings.