Chop 2 green onions into 2” (5 cm) sticks. Slice the remaining 2 green onions into thin slices.
Prepare a steamer by adding 2” (5 cm) water into the pot. Cover and heat over medium-high heat until boiling.
Use a plate that can fit into your steamer rack. Spread the green onion sticks onto the plate to make a bed. Place the chicken breast on top. Sprinkle salt evenly over the chicken.
When steam comes out of the steamer, place the steamer rack with the chicken on top, and cover the steamer. Cook for 20 minutes. Test the chicken by using a thermometer inserted into the thickest part. It should read 165 degrees F (73 C). Or insert a knife into the thickest part, and the juice should run clear. If the chicken is still pink inside, steam for another 5 to 10 minutes. Once done, transfer the chicken to a plate to cool.
While cooking the chicken, combine the rest of the ingredients in a large bowl. Whisk to mix well.
Once the chicken is cooled, transfer it onto a cutting board. Use a meat pounder or a rolling pin to pound the chicken (optional), then shred into thin slices using two forks.
Place the chicken into a large bowl or deep plate. Drizzle the sauce on top and mix well. Garnish with thinly sliced green onion. If you want to create the authentic look, like at a Sichuan restaurant, drizzle more chili oil (about 1/3 to 1/2 cup) onto the chicken.
Serve as a cold appetizer or a main dish.