Preheat oven to its lowest possible temperature (my oven has a minimum temperature of 170 degrees). Line a baking sheet with parchment paper.
On one side of the baking sheet, spread the lemon zest in a single layer, separating any clumps with your fingers. On the other side, add the whole peppercorns.
Bake until the zest is completely dried, about 35 to 45 minutes. Check occasionally and stir to redistribute any bright yellow clumps of zest (you'll know the zest is dry when it turns a light orange color and feels crunchy).
Transfer the peppercorns to a spice grinder and pulse until finely ground. Add dried zest and pulse until finely ground. In a small bowl, add black pepper and lemon zest mixture, then stir in salt. Store covered in the pantry for up to 6 months.
Lemon zest: 1/2 cup dried lemon peel granules may be substituted for the fresh lemon zest (omit the oven instructions entirely).
Black pepper: Substitute 1 1/2 tablespoons freshly ground black pepper for the whole peppercorns.
Yield: This recipe makes about 6 tablespoons seasoning, about 8 servings (assuming 2 teaspoons per chicken breast or thigh or enough to season 2 whole chickens).
Storage: Store covered in a dark place for up to 6 months.
Usage: Use to taste (I like 1 1/2 to 2 teaspoons seasoning per chicken breast or thigh and 3 tablespoons per whole chicken. For wings, I use a LOT).
Toaster oven: This method also works in a toaster oven.