Prepare the citrus salad

• Toss the arugula, cherry tomatoes, radish and orange segments in a bowl.
• Dress with the olive oil and lemon juice, season with salt and pepper and set aside.

Coat the tuna in sesame

• Season the tuna steak with salt and pepper.
• Press the black sesame seeds all over the tuna until fully crusted.

Sear the tuna

• Heat a lightly oiled frying pan over high heat.
• Sear the tuna on each side, keeping the centre rare.
• Remove from the pan and slice into thick pieces.

Plate and top with caviar

• Arrange the citrus salad on plates.
• Lay the sliced sesame-crusted tuna on top.
• Spoon the black caviar over the tuna and serve.