Season the sirloin steaks liberally with salt and let them sit at room temperature for 30 minutes while you prepare the charcoal grill.
Prepare the grill for a two-zone fire by lighting charcoal until it's mostly ashed over in a chimney. Pour the charcoal to one side of the grill, put the grate on top, and clean it if necessary. Allow the grill to heat for 5 minutes with the lid on.
To grill the steaks, season with oil, Ooomami blend, salt, and pepper. Grill for 2-3 minutes, rotate for grill marks, and cook for another 2 minutes. Flip the steaks, sear for 2 minutes, then move to the cooler side. Cover and cook to desired internal temperature, like 130°F for rare.
Remove the steaks from the oven and rest with a pat of butter, or umami compound butter, on top for 5 minutes.
Slice against the grain into thin strips to serve.