Pour the stock into a pan, bring to the boil and add the bulgar. Cook, uncovered, over a medium heat, for 7 minutes. Cover with a tight-fitting lid and set aside for 6–7 minutes, until the liquid has been absorbed and the grains are tender.
Meanwhile, heat a ridged griddle pan over a medium-high heat. Rub 1 tablespoon of the oil over the tuna steaks and season with salt and pepper. Cook them in the griddle pan for 2–3 minutes on each side, until nicely charred and cooked to your liking. Set aside and keep warm.
Gently stir the remaining ingredients into the bulgar, then replace the lid for 3–4 minutes. Spoon the warm mixture into bowls and serve topped with the griddled tuna.