Season the salmon fillet with sea salt and black pepper on all sides.
Heat avocado oil in a non-stick skillet over medium-high heat and sear the salmon until the skin is golden and crispy.
Remove salmon from heat, let it rest for a minute, then flake it into thick chunks.
In a small bowl, toss the cooked sushi rice with rice vinegar until well combined.
Lay the nori sheet on a bamboo rolling mat and spread the rice in a thin, even layer, leaving the top inch clear.
Arrange the flaked salmon, avocado slices, and julienned cucumber in a horizontal line across the center of the rice.
Whisk together the Greek yogurt and sriracha, then drizzle the mixture over the filling.
Carefully roll the nori from the bottom up, using the mat to keep it tight, and seal the edge with a drop of water.
Use a sharp, wet knife to slice the roll into eight pieces and serve with coconut aminos for dipping.