Rub the steak heavily with salt, pepper and cumin. Drizzle with red wine vinegar. Allow to marinate on the counter and come to room temperature. Slice the bell peppers, toss with olive oil, and place in a grilling basket.
Heat the grill to medium-high heat.
Place the steak over direct heat and allow to cook for about 5 to 8 minutes. Flip the steak with tongs. Cook until interior temperature reaches your desired level.
Slice the steak thinly using an electric knife. Serve with flour tortillas, grilled bell peppers, and toppings of your choice.