Sprinkle 1 teaspoon of salt on the salmon and let it sit for 10 minutes. Pat dry with a paper towel to remove excess moisture.
Cook the salmon in a preheated frying pan over medium heat for 3-4 minutes. Flip and cook for another 2-3 minutes, or until golden brown and cooked through. Remove from heat and flake into small pieces.
Slice cucumber very thinly using a sharp knife or mandoline. Sprinkle with 1/2 teaspoon of salt and let sit for 5 minutes. Gently squeeze out excess water using your hands or a clean kitchen towel.
Remove pits from Umeboshi pickled sour plums, then finely chop into a paste using a knife.
Rinse the steamed rice under cold running water, and drain well.
Divide the rice between 2 large bowls. Top each bowl with the flaked salmon, cucumber slices, and umeboshi paste. Sprinkle with shredded nori. Gently pour ice-cold green tea over until the rice is just covered. If desired, add a splash of soy sauce for extra flavor.