Toast the pepitas in a small pan over medium heat. This should only take a few minutes and you'll know it's done when you smell a nice nutty aroma.
Add the shredded brussels sprouts, pomegranate arils, pepitas, and grated parmesan to a medium sized bowl.
Combine the lemon juice and olive in a small bowl.
Thinly slice the apples and then add to the small bowl of lemon juice and olive oil. Let this sit for a few seconds before transferring it over to the medium bowl, then add the salt and pepper.
Toss to combine. Add a bit more salt and pepper (to taste) if necessary, then either serve or put in the fridge until you're ready to do so!