Simmer 225g of boneless, skinless chicken thighs in 4¼ cups of water with ½ medium onion, 1 teaspoon of kosher salt, 1 teaspoon of sugar, and ½ teaspoon of MSG until it reaches 165°F / 74°C. Cool and shred.
Soak 1 thinly sliced medium white onion in water briefly and drain. Pickle in 1 tablespoon of vinegar and 2 tablespoons of cold water for 10-15 minutes, then drain.
Whisk 2 tablespoons of fish sauce, 4 tablespoons of white vinegar, 4 tablespoons of water, and 2 tablespoons of sugar until the sugar dissolves.
Toss 3 cups of thinly shredded green cabbage and 1 cup of julienned carrot with the chicken, onion, ½ cup of chopped cilantro, 1 bunch of rau ram leaves, and 1 sliced large red chili. Dress right before serving.
