Brine the salmon for best results. This both seasons the fish and helps keep the albumin from being released (that white exuded protein that you often find on cooked salmon). Mix 1 tablespoon of kosher salt or 1/2 tablespoon of fine grain table salt per cup of cold water. About 4-5 cups is generally enough to cover the salmon. Brine for 30 minutes to 1 hour in the refrigerator.
Remove salmon from the brine and pat dry. Add half the orange oil or zest and a tiny splash of soy. Rub into the salmon and place the filets into a sous vide safe bag (I like to use silicone bags). Cook sous vide at 110ºF for 1 hour. Alternatively, you can slow roast the salmon as well.
While the salmon cooks, prepare the fruit, sauce, and mint. To make the sauce, combine the remaining orange oil, soy, monk fruit, sriracha, lemon juice, and xanthan gum in a small blender. Blend until completely combined. The sauce should be thickened so that it just coats the back of a spoon. Taste and adjust seasoning as desired with more soy, sweetener, sriracha, and/or lemon. Set aside.
Add the avocado oil to a small microwave-safe dish and add 1/4 cup of the mint leaves. Coat evenly in oil and then microwave the dish containing oil and leaves for 30-60 seconds on full power. They are done with they are uniformly darker and become slightly less opaque. Use a fork to transfer them to a paper towel lined plate and sprinkle with salt. Set aside.
To serve, place the melon ribbons onto a serving dish. Finely chop the remaining mint leaves and sprinkle over top. Remove the salmon from the bags and carefully transfer to the top of the melon ribbons. Spoon sauce over top, sprinkle a bit of shichimi togarashi over the salmon, and garnish with the fried mint leaves.