Costco's Ahi Tuna Saku Block is a premium cut of Yellowfin tuna sourced from Costa Rica, sold fresh by the pound at the service deli counter. The saku cut is a rectangular block specifically shaped for clean, uniform slicing, making it ideal for sashimi, poke bowls, and seared tuna preparations.

This tuna is of sashimi-quality grade and is versatile enough for both raw and cooked applications. For the best results when cooking, pat the block dry before searing and cook for approximately 45 seconds per side over high heat to achieve a rare center. When preparing raw, thaw overnight in the refrigerator and slice against the grain into clean, even pieces. Avoid over-marinating — no more than 15 minutes — to preserve the delicate texture.

The saku block format provides consistency and minimal waste, making it a popular choice among home cooks and seafood enthusiasts looking for restaurant-quality tuna at a competitive price point.