1. Add water to a Dutch oven to a depth of 1 inch; bring to a simmer. Place chicken in a vegetable steamer. Place steamer in pan over water; cover. Reduce heat to medium-low. Steam, covered, 10 minutes. Remove chicken from steamer; cool. Pat dry.
2. Heat a large skillet over medium-high heat. Add oil; swirl to coat. Add chicken to pan; sauté 5 minutes, turning to brown on all sides. Add green onions and ginger to pan; sauté 30 seconds, stirring constantly. Remove pan from heat; transfer chicken mixture to a large bowl using a slotted spoon.
3. Combine chili sauce, Sriracha, rice vinegar, and fish sauce, stirring well. Drizzle chili mixture over chicken; toss.