Refrigerate the serving plate or bowl until ready to serve.
Make sure the fish is very fresh and there are no bones or skin on the fillet.
Cut the fish into 1/3rd inch cubes. Keep cold until ready to serve.
Cut the top and bottom off of the orange.
Use a sharp knife to cut away the pith.
You should be left with a skinless orange without any pith left behind.
Use a knife to cut in between the membranes and cut out each orange segment.
Cut the orange segments into roughly 1/3rd inch pieces. Set orange pieces aside until ready to plate.
Use a very sharp knife to slice the jalapeno into super-thin slices. You will only need about 8-10 slices. Set the jalapeno slices aside until ready to plate.
Don't cut the avocado until you are ready to serve the dish. If you cut it too soon it will start to brown on you. You will only be using half of the avocado, save the other half for another application.
Cut the avocado half into 2 pieces to yield quarters.
Peel back the skin from each quarter avocado. Use a spoon if necessary.
Cut each quarter avocado in half again to yield 1/8ths and then cut these wedges into 1/3 inch chunks.
On a cold plate, evenly place all of the diced fish.
Drizzle all of the citrus-soy dressing over the fish and onto the plate. Randomly arrange the rest of the ingredients on the plate (orange, avocado, jalapeno slices, cilantro, and the reserved scallion greens). The dish should not need any additional seasoning but give it a taste and if you feel it needs an adjustment, sprinkle on a little salt and/or lemon juice.