
In a medium bowl, toss the chicken with the cornstarch and salt until evenly coated.
Heat a large nonstick skillet over medium-high heat and add the oil. Spread the chicken pieces in a single layer and cook for 6–8 minutes, turning once, until lightly browned and just cooked through.
While the chicken browns, whisk together water, peanut butter, soy sauce, honey, rice vinegar, garlic, ginger, and sriracha in a measuring cup.
Reduce heat to medium. Pour the peanut sauce into the skillet and stir to coat the chicken. Simmer 2–3 minutes, stirring, until the sauce is glossy and clings to the pieces.
Serve hot over rice, spooning extra sauce on top, and garnish with green onions.