Clean the frisée, rinse and drain well. Clean the spring onions and cut the white and light green lengthwise into very fine strips. Place in cold water and leave until ready to serve. Pluck off cilantro leaves and place flat in cold water, this will curl the onion strips and keep the cilantro greens crisp. Peel cucumber, cut in half lengthwise and scrape out seeds with a teaspoon. Cut cucumber lengthwise into very thin strips.
Season with 1 tbsp. oil, 1 tbsp. vinegar, 1 pinch each of salt and sugar.
For the salad dressing, stir together remaining vinegar, lime juice, remaining oil, olive oil, liter pinch of salt and maple syrup. Toast sesame seeds in a frying pan without fat until golden.
For the avocado cream, cut the fruit in half and remove the pit. Lift out flesh with a tablespoon and mash finely in a mixing bowl with lime juice, yogurt, milk, i pinch each of salt and sugar. Cover the cream directly with foil and leave to cool.
Frisée, green onions and cilantro greens together and drain the cucumbers separately in strainers.
4. cut tuna lengthwise into 2 rectangles of even thickness, if possible, and season with pepper. Remove the peel from the ginger and roughly slice. Heat a coated frying pan very high. Add oil and fry the pieces of fish over very high heat for 30 seconds on each side. Remove the fish. Add the ginger and chili pepper to the frying pan, add to the oil and fry.