Seared Tuna Steak (Rare-Center, 90 Seconds Per Side)
By Yuki Tanaka · Seafood Specialist · Updated 2026-05-08
1-inch thick ahi tuna steak seared 90 seconds per side in butter. Salt only — no soy, no sesame. Rare center, crusty exterior. The 4-minute carnivore dinner.
Carnivore seared tuna steak is a 1-inch thick ahi (yellowfin) tuna steak salted and seared in 1 tablespoon of butter over screaming-hot heat for 90 seconds per side — total 3 minutes — leaving a rare red center with a thin crust. Salt is the only seasoning. The 90-second-per-side timing is non-negotiable; longer cook times turn ahi tuna from sushi-grade luxury into dry chalky disappointment. Pull at 110°F internal where the rare center is preserved. A 6-ounce cooked serving delivers 40g protein, 5g fat, and 200 calories — nearly all-protein with minimal fat, ideal for body-recomposition tracking. Sushi-grade ahi tuna costs $20 to $35 per pound at quality fish counters; a single 6-ounce steak runs $8 to $14. Most blind tasters describe seared tuna as 'meatier than salmon,' closer to a beef steak in mouthfeel than to other fish. Source matters: only sushi-grade tuna should be cooked to a rare center.
Ingredients
| Ingredient | Protein | Fat | Calories |
|---|---|---|---|
| 6 oz ahi tuna seared (per serving) | 40g | 1g | 140 |
| 1 tbsp butter | 0g | 4g | 60 |
| Coarse salt | 0g | 0g | 0 |
| Per serving | 40g | 5g | 200 |
Macros per serving (after cooking and any fat draining). Source: USDA FoodData Central.
Instructions
- 1
Remove tuna from fridge 15 minutes before cooking — slightly tempered fish sears better than ice-cold.
- 2
Pat completely dry with paper towels. Salt both sides with ½ tsp coarse salt.
- 3
Heat a 10-inch cast iron skillet over high heat for 5 minutes until smoking — the pan must be screaming hot.
- 4
Add 1 tbsp butter. As soon as it foams, add the tuna steak.
- 5
Sear 90 seconds without moving. Flip with a spatula.
- 6
Sear the second side 90 seconds.
- 7
Optional: stand the steak on its narrow edges and sear for 30 seconds each (4 short sides) for a fully encased crust. Skip if the rare center is the priority.
- 8
Transfer to a cutting board. No rest needed (rare center is already perfect). Slice against the grain in ½-inch slabs.
Nutrition per Serving
Frequently Asked Questions
Why only 90 seconds per side?
Ahi tuna is best cooked to rare-center (about 110°F internal). Each additional 30 seconds per side at high heat adds 10 to 15°F to the interior. 90 seconds gets you a thin crust and a rare red center — the iconic seared-tuna eating experience. 2 minutes per side gets you medium and the texture noticeably toughens. 3 minutes per side gets you medium-well and the result tastes like canned tuna in shape. Don't overcook ahi.
Why no soy sauce or sesame?
Both are plant-derived and excluded from strict carnivore. Soy sauce is fermented soybeans; sesame seeds are seeds. The classic seared-tuna preparation in Japanese-American restaurants uses both for the iconic 'pepper-crusted ahi' look and the soy-based dipping sauce. Strict carnivore versions skip both. The result is purer-tasting tuna where the fish flavor dominates. Salt-only seasoning lets the high-quality ahi stand on its own.
What's sushi-grade tuna?
There's no formal USDA grade for 'sushi-grade' fish. In practice the term means: yellowfin (ahi) or bigeye tuna that's been flash-frozen to -20°F or lower, killing any parasites. Frozen-then-thawed tuna meets sushi-grade standards; never-frozen 'fresh' tuna can carry parasites. Look for vacuum-sealed packs labeled 'previously frozen' or 'flash-frozen at sea' — those are the sushi-grade standards. Whole Foods and quality fish counters reliably stock it; supermarket meat-counter tuna often doesn't.
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