Crush the peppercorns using the back of a pan, a mortar and pestle, or a blender. If you use a blender, pulse the peppercorns—do not run the blender at full speed, as this will grind it too finely. Combine and reserve for chicken. Zest the lemons with a mortar and pestle. Add the Maldon salt. Crush the zest and salt together until fragrant and broken down. Store in an airtight container, in a plastic or ceramic container wrapped tightly with plastic wrap, or in a ziplock bag in a cool, dry place for up to 2 weeks.