Mix the chicken and Sriracha sauce together until well coated. Saute the chicken in oil until browned and almost done. Set aside.
Add the chicken stock garlic, lemongrass paste, chili paste, ginger, soy sauce, and the seasoning packets from ramen noodles together in a large pot. Bring to a boil. Reduce to a simmer and add the mushrooms and green onions. Simmer 3 minutes. Stir in the ramen noodles and cook 4 minutes. Stir in the chicken.