Make the chimichurri: In a medium bowl, combine the cilantro, mint, chives, garlic, and red wine vinegar. Whisk in the olive oil. Season with salt and pepper to taste. Set aside.
Prepare the steak: Heat a large cast-iron pan or griddle over medium-high. Rub each steak with the olive oil and season generously on both sides with salt and pepper. Gently lay the steaks in the skillet and cook for 2 to 3 minutes, until a dark brown crust forms. Flip and sear the other side until the steaks reach an internal temperature of 120 degrees F. Flip steaks as needed to acheive even browning. Allow the steaks to rest on a wire rack for 5 minutes.
To serve, divide rice, beans, and sliced avocado among individual bowls. Slice the steak against the grain, then top each bowl with shingles of the steak. Spoon chimichurri over the steak.