Pat the salmon dry and slice the salmon into small cubes. Season with salt and pepper.
Heat the avocado oil in a pan over medium heat and add the salmon. Cook for about 2-3 minutes on each side or until cooked through. Add the coconut aminos and lime juice at the end and stir to scrape up any stuck pieces of salmon on the bottom of the pan, and coat the salmon. Remove from the pan and set aside.
Wash the cucumber well, slice off the ends, and slice it in half vertically. Scoop out the inside of the cucumber until the cucumber is fully hollowed out.
Assemble the boats by filling with rice, then topping with salmon, avocado, spicy mayo, and green onion. Serve fresh.