Pat the steak dry. Use paper towels to remove surface moisture. Dry steak sears better and browns more evenly.

Mix the marinade. In a small bowl, combine olive oil, tamari, lemon juice, garlic, smoked paprika, pepper, salt, onion powder, and red pepper flakes if using.

Marinate briefly. Place the steak in a shallow dish or zip-top bag. Pour the marinade over and coat well. Marinate at room temperature for 20–30 minutes (or refrigerate up to 8 hours and bring to room temp before cooking).

Preheat your pan. Set a large cast-iron or stainless-steel skillet over medium-high heat for 3–5 minutes until very hot. Add 1 tablespoon olive oil and swirl to coat.

Sear the steak. Lay the steak in the hot pan without crowding. Do not move it for 3–4 minutes to build a crust. Flip and sear the second side for 3–4 minutes more.

Check doneness. For medium-rare, aim for an internal temperature of 130–135°F (54–57°C). For medium, 140°F (60°C). Use an instant-read thermometer for accuracy.

Rest the steak. Transfer to a cutting board and let rest 5–10 minutes. Resting keeps juices in the meat.

Slice against the grain. Identify the direction of the muscle fibers and slice thinly across them at a slight angle for tenderness.

Finish and serve. Sprinkle with chopped herbs and a pinch of salt. Serve with lime wedges and your favorite low-carb sides like sautéed spinach, roasted broccoli, or cauliflower rice.