Now that Peter had a system of his own, he was ready to take names, kick ask and prove himself.
And so, there they were, him and Asmodeos, before a slime cave, ready to take out every single slime there was.
It was the beginning of their adventure, and not only their adventure, but their career. Those slimes were easy to kill. You hit them with a broom, take their cores, eat the cores, and then proceed to another slime.
That, which Asmodeos couldn't understand, was, what Peter hoped to achieve with such a thing. Slimes were not a very good source of energy, and they already had the fruit and vegetables from the cave.
But still, Peter waved the broom, ate the nuclei, and followed the loaf of bread's advice. Which was: eat as much as you can, when you feel sick drink water, rest up, and then eat some more.
That would have been a very bad advice if the loaf of bread was actually a doctor.