Combine all spice rub ingredients except brown sugar and salt in a bowl. Dry fry in a fry pan for about 2 minutes, stirring constantly until fragrant. Remove and allow spice rub to cool. Mix in brown sugar and salt.
Sprinkle each piece of steak generously with spice rub on both sides. Allow flavors to develop for 30 minutes.
Store remaining spice rub in an air tight jar.
Preheat the grill to high. Brush some oil on the grates.
Place steaks on the grates and close the lid. Grill steaks for 7 to 9 minutes** on each side for medium doneness. Watch closely to avoid flare-ups by opening the lid occasionally. Move steaks to a different part of the grill to avoid charring if flare-ups occur.
Flip only once.
Transfer steaks to a platter. Cover loosely with aluminum foil and allow them to rest for 10 minutes.
Notes
Grilling times are approximate only as it depends on the thickness of the steaks, heat source for grill, and desired doneness.