Tuna with pak choi
Put the pieces of tuna in a single layer in a glass or ceramic dish. Sprinkle the chillies and garlic over the tuna, and pour the wine over the top. Cover and marinate in the refrigerator for 1 hour.
Lift the tuna out of the marinade, drain on kitchen paper and season with a little salt.
Pour the marinade into a small pan, season with salt and pepper, then simmer for a few minutes until reduced by about half. Remove from the heat, cover and keep warm.
Heat a ridged cast-iron grill pan until very hot. Dip a wad of kitchen paper in oil, and wipe it over the hot pan. Put the tuna in the pan, and chargrill for 3–4 minutes.
Heat the remaining oil in a wok or large deep frying pan until very hot. Add the pak choi and mushrooms, and stir-fry over a high heat for about 3 minutes. Season with salt and pepper.
To serve, cut the tuna fillets in half, mound the vegetables on warmed plates and top with the tuna and marinade. Serve hot.