If toasting coriander seeds, heat a small dry skillet. Add whole coriander seeds and toss or stir frequently until fragrant (about 2 minutes). Cool and grind in spice mill or using a mortar and pestle. In a medium bowl, mix together ground coriander, coffee, salt, brown sugar, cocoa powder, and pepper. Prepare a grill or grill pan for medium high heat by lightly oiling pan. Pat the steaks dry. Season steaks generously on both sides with rub. Grill steaks, turning occasionally, until lightly charred and cooked to desired doneness, 8–10 minutes for medium-rare. Transfer to a cutting board and let rest 10 minutes, then slice against the grain. Serve with Tomato Chutney.