Heat a skillet over medium-high heat. Brush the tuna steak with sesame oil and sear for about 30 seconds on each side until the outside is browned but the inside remains rare. Remove from heat and let it cool.

Coating the Tuna

Once cooled, brush the tuna with soy sauce and roll it in the mixed sesame seeds until well coated. Slice thinly.

Making the Salad

Preparing the Salad Ingredients

Julienne the cucumber and mango, and dice the red bell pepper. Combine all salad ingredients in a bowl.

Dressing the Salad

In a small bowl, whisk together lime juice, olive oil, and salt. Pour over the salad and toss gently to combine.

Plating

Assembling the Dish

On a serving plate, arrange the sliced tuna tataki. Serve alongside the cucumber and mango salad, topped with crispy pickled ginger and a drizzle of ponzu sauce.