An ever-so-slightly modified version of the recipe of Elizabeth Green found in Epicurious
• 4 medium peaches, about 1½ pounds
• ¾ cup sugar
• ½ cup cider vinegar
• 1/8 teaspoon hot red-pepper flakes (*)
• ½ red onion
• ¾ teaspoon salt
. Peel the peaches. Cut all into ½ inch slices. Take half the slices and further cut them in half.
. Chop the red onion very finely -- you should end up with about ½ cup.
. Place the peach slices into a small saucepan and add the sugar, vinegar, and hot pepper flakes.
. Place the saucepan over medium-high heat and bring the mixture to a brisk simmer.
. Reduce the heat and simmer for 20 minutes stirring fairly often.
. Add the onion and the salt and continue to simmer for five more minutes, stirring occasionally.
. Allow to cool to room temperature.
Epicurious used this to accompany pork chops. I used it with deep-fried cod.
(*) The original recipe called for ¼ teaspoon red pepper flakes. Maybe I have ultra-hot flakes but this quantity made the relish too hot for Margot. Use an amount between 1/8 and 1/4 to suit your (and your guests') taste.