Mustard Sauce - Mix the Grey Poupon Mustard, soy sauce and dry mustard in a bowl, then transfer to a bottle and shake well.
Vegetables - Heat olive oil in saucepan, combine green bell pepper,
red bell pepper, spanish onion, oregano, white pepper, salt , and saute for one to two minutes.
Mix spices together, then season the tuna with them on all sides. Sear tuna on all sides in a pre-heated hot pan with 4 tbsp (60 ml) of olive oil. Slice the cooked tuna into 1/4 inch thick slices. Place the sliced tuna on a dinner plate, spreading the tuna from one end of the plate to the other. Place cooked vegetables next to the tuna, and the mustard sauce in the corner.