Preheat the oven to 375 degrees F (190 degrees C).
Whisk coconut milk, water, soy sauce, curry paste, garlic, ginger, and sesame oil together in a 9x13-inch baking dish.
Reserve 3 tablespoons green onions for topping and add remaining onion to baking dish.
Add chicken pieces and 1 spice packet from the ramen; discard remaining seasoning packets.
Toss chicken to coat.
Add ramen noodles and nestle them into the coconut milk mixture with the chicken pieces surrounding them, taking care to make sure the chicken is not underneath the noodles.
Cover the dish with foil.
Bake in the preheated oven for 22 to 24 minutes.
Flip noodles over to submerge the second side, cover, and bake for another 5 minutes.
Toss everything together until well combined with the sauce and sprinkle with reserved green onions.
Serve with Sriracha.
