Last year was the year I dialed this in. It took a handful of reps / opportunities but I am now a true tuna collar evangelist. The first key is you need to treat the cut with serious care. Meticulously trim out bloodline bits that do show up in weird places. White membrane / connective tissue is fine to stay. And never let it touch freshwater / ice, just as you would ensure with loin meat. Clip those pec fins, chop or saw it into four pieces. You are now ready to see the light. You don’t need a