Begin by making the candied pepitas. Line a sheet pan with parchment paper.
Add pepitas to a medium nonstick skillet set to medium-high heat, and toast for 3-5 minutes. Some of the seeds will brown a bit, and you’ll be able to smell a toasty scent. Careful not to burn them—turn down the heat if you smell burning instead of toasting.
Remove pepitas from skillet and set aside.
Add sugar, butter, piment d’Espelette, and salt to the warm pan. Turn down the heat to medium.
Cook sugar and butter mixture until sugar melts and mixture is smooth, stirring frequently. This should take about 5 minutes.
Quickly stir in pumpkin seeds, using a rubber spatula to try to coat each seed.
Pour seeds onto parchment lined-tray and spread into a single layer using the spatula.
Let cool, then break into chunks with your fingers.
While candied pepitas are cooling, make the salad dressing by whisking together all ingredients in a medium bowl. Taste and season with more salt and/or pepper if desired.
Chop apples into ½-inch chunks, discarding the cores.
Chop cheddar cheese into ½-inch chunks.
Thinly slice red onion.
To assemble salad, toss together arugula, quinoa, apples, cheddar cheese, and red onion in a large bowl.
Garnish with candied pepitas, and drizzle with honey mustard dressing.
Notes
Apple recommendations: I like to use a semi-tart apple for this dish, like Pink Lady, Gala, or Honey Crisp apples. Pepitas: In case you are unfamiliar with this ingredient, pepitas are pumpkin seeds that have had their white outer husks removed. If you don’t have pepitas, you can substitute candied nuts of any kind (pecans, walnuts, etc.) or even plain (not candied) nuts. Piment d’Espelette: Piment d’Espelette is a French chili pepper, grown mostly in the Basque region of France. It is a fairly mild pepper, but does add a little bit of heat to the chicken in this dish. You can substitute a mild chili powder or paprika (smoked or plain) if you don’t have piment d’Espelette. Make-Ahead Directions: Cooked quinoa will last several days in the refrigerator, so you can make that in advance, along with the honey mustard dressing. The candied pepitas can also be made in advance and kept at room temperature for about 5 days. When you’re ready to serve, chop the apples and cheddar cheese, and put all the ingredients together.