Decoding Multi Level Json

Below is the json I get after encoding it using Jason

"{\"topic\": \"dummy_topic\", \"msg\": \"{\"fruit\":\"apple\",\"dish\":\"apple-pie\"}\"}"

I am trying to pass it as the body of the request while calling an API using HTTPoison , it gives me the json decode error

tried the same on terminal and I get below ,

iex(10)> var = "{\"topic\": \"dummy_topic\", \"msg\": \"{\"fruit\":\"apple\",\"dish\":\"apple-pie\"}\"}"
"{\"topic\": \"dummy_topic\", \"msg\": \"{\"fruit\":\"apple\",\"dish\":\"apple-pie\"}\"}"
iex(11)> Jason.decode(var)                                                                              
{:error,
 %Jason.DecodeError{
   data: "{\"topic\": \"dummy_topic\", \"msg\": \"{\"fruit\":\"apple\",\"dish\":\"apple-pie\"}\"}",
   position: 35,
   token: nil
 }}

Which is the exact same error I get when when I use HTTPoison ,

my expectation is I should be getting something like below when I use Jason.decode ,

%{
  "topic" => "dummy_topic",
  "msg" => %{"fruit" => "apple", "dish" => "apple-pie"}
}

Do you know where I am getting it wrong or what can be done to get the expected output ?