Guide to Change Menu
After you have learned more recipes, go to the blackboard that shows the pricing of your menu and click on it.
It should let you add up to 5 recipes and change which is your daily special along with the other choices.
And you need to change it before the new grocery order (until you stock the fridges in the kitchen, you can have the orders delivered and still change the menu).
Also you can only remove the 4th and 5th recipes so if you want to remove 1st/2nd/3rd , you have to swap them around first.