Solution: Applying Template Pattern

abstract class Burger {
  final public function make()
  {
    return $this->layBread()
                ->spreadSauce()
                ->addLettuce()
                ->addPrimaryToppings();
  }

  protected function layBread()
  {
    var_dump('lay bread');

    return $this;
  }

  protected function spreadSauce()
  {
    var_dump('spread Sauce');

    return $this;
  }

  protected function addLettuce()
  {
    var_dump('add lettuce');

    return $this;
  }

  protected abstract function addPrimaryToppings();
}

Now, subclass extending Burger can add its own implementation for addPrimaryToppings().

class ChickenBurger extends Burger {
  protected function addPrimaryToppings()
  {
    var_dump('add chicken');

    return $this; 
  }
}

class VeggieBurger extends Burger{
  protected function addPrimaryToppings()
  {
    var_dump('add veggie');

    return $this; 
  }
}

Problem: Without Template Pattern

class ChickenBurger {
  public function make()
  {
    return $this->layBread()
  	              ->spreadSauce()
  	              ->addLettuce()
  	              ->addChicken();
  }

  public function layBread()
  {
    var_dump('lay bread');

    return $this;
  }

  public function spreadSauce()
  {
    var_dump('spread Sauce');

    return $this;
  }

  public function addLettuce()
  {
    var_dump('add lettuce');

    return $this;
  }

  public function addChicken()
  {
    var_dump('add chicken');

    return $this;
  }
}

To make another burger, say Veggie Burger, we need to copy many similar functions from the ChickenBurger Class.

class VeggieBurger {
  public function make()
  {
  	return $this->layBread()
  	            ->spreadSauce()
  	            ->addLettuce()
  	            ->addVeggie();
  }

  public function layBread()
  {
    var_dump('lay bread');

    return $this;
  }

  public function spreadSauce()
  {
    var_dump('spread Sauce');

    return $this;
  }

  public function addLettuce()
  {
    var_dump('add lettuce');

    return $this;
  }

  public function addLettuce()
  {
    var_dump('add veggie');

    return $this;
  }
}