How to Make It
In a medium bowl, whisk the vinegars with the olive oil and sugar. Stir in the shallot, parsley, cilantro, chives and oregano and season with salt and pepper. Let the chimichurri stand for at least 20 minutes and for up to 2 hours.
In a small bowl, mix the ground coffee with the chile powder, brown sugar, paprika, cumin and salt. Pat the steaks all over with the coffee-chile rub and let stand at room temperature for 30 minutes.
Light a grill or preheat a grill pan; oil the grates or pan. Grill the steaks over moderate heat, turning once, until they’re nicely charred outside and medium-rare within, 11 to 13 minutes. Transfer to a platter and let rest for 10 minutes.
In a large bowl, toss the cilantro, parsley, chives and shallot. Add 3 tablespoons of the chimichurri, season with salt and pepper and toss to coat the herbs.
Thinly slice the steaks and arrange on the platter; spoon some of the chimichurri on the meat. Serve with the herb salad. Pass the remaining chimichurri on the side.
The chimichurri sauce can be refrigerated overnight. Bring to room temperature before serving.