Whisk brown sugar, vinegar, fish sauce, garlic, ginger, hot sauce, and soy sauce together in a large bowl.
STEP 2
Place chicken in a separate bowl. Add 1/4 cup brown sugar sauce; toss until chicken well coated. Set aside 15 minutes.
STEP 3
Heat vegetable oil in a heavy skillet over high heat until oil starts to smoke. Add chicken in a single layer; cook and stir until chicken starts to caramelize and turn deep brown, 8 to 10 minutes. Reduce heat to medium. Stir in jalapeños and red peppers, peanuts, and 1/2 cup green onions; cook and stir, 1 minute. Add remaining brown sugar sauce; simmer until heated through, 1 or 2 minutes. Remove from heat.
STEP 4
Stir in cilantro. Serve over hot cooked rice; top with chopped green onions.