It's a function that takes in a day of the week and returns a taco.
Recursion Level 3: The Toppings
Recursion Level 2: The Fillings
Recursion Level 1: The Base Case
Recursion Level 4: The Toppings Toppings, a function within a function.
Recursion Level 5: The Toppings Toppings Toppings Toppings, a function within a function within a function.
Recursion Level 5/4: The Toppings Toppings Toppings Toppings Toppings
Recursion Level 8: The Toppings Toppings Toppings Toppings Toppings Toppings, a function within a function within a function within a function.
Recursion Level 8/5: The Toppings Toppings Toppings Toppings Toppings Toppings Toppings Toppings