How to save JSON array with objects inside Rails JSON column?

I have a Kitchen model and I want to add menu list called special_kitchen_menus into it.

I can update the kitchen. But, I get this when I console.log() the result from database:

[{"name"=>"pizza", "price"=>29}, {"name"=>"burger", "price"=>24}, {"name"=>"cake", "price"=>39}]

Line of code that do the console.log()

var a = "<%= @kitchen.special_kitchen_menus %>";
console.log(a);

I try to use serialize and create my own method called convert_to_hash. But I got no luck at all.

schema.rb

create_table "kitchens", force: :cascade do |t|
    # other columns
    t.json     "special_kitchen_menus",  default: {}
end

kitchen model

class Kitchen < ActiveRecord::Base
    # serialize :special_kitchen_menus

    # def convert_to_hash
    #   self.special_kitchen_menus = self.special_kitchen_menus.to_h
    # end
end

kitchen controller

# before_action :convert_to_hash, only: [:update]

def update
    @kitchen = Kitchen.find(params[:id])
    if @kitchen.update(kitchen_params)
      redirect_to @kitchen
    else
      render :edit
    end
end

def kitchen_params
    params.require(:kitchen).permit(:special_kitchen_menus)
end

form

<%= form_for @kitchen do |f| %>
    <!-- other fields -->

    <label>Special Kitchen Menus</label>
    <%= f.text_field :special_kitchen_menus %>              
    <%= f.submit "Update" %>
<% end %>

sample data for update

[
  { "name": "pizza", "price": 29 }, 
  { "name": "burger", "price": 24 }, 
  { "name": "cake", "price": 39 }
]

What should I do to update the input data correctly so that I can retrieve it back correctly just the input data without that weird characters?

Note 1: I don't want to store the data in another model OR use nested attribute. I just want to store the data inside this Kitchen model using the same Kitchen's form.

Note 2: I'm using postgres database. Not sqlite for this app.