Set aside the peaches you want to use for decoration at the end, about 3.
Cut a shallow X in the bottom of each peach. Bring a large pot of water to a boil, and also set up a large bowl with ice water.
When the water in the pot boils, place the peaches in it for 15 to 20 seconds, then take them out and immediately place them in the bowl of ice water.
After a few seconds, you should be able to peel the skins off with your fingers.
Slice the peeled peaches in half and remove the pit.
Make the puree by mashing the peaches with a potato masher or a blender until smooth.
Measure 4 cups (1 L) of the puree into another bowl. Taste the puree and add sugar to taste.
In a large bowl, combine the cream and the sherry. Whisking constantly, slowly add the 1 cup (200 g) of sugar.
Whisk in the peach puree until it’s all evenly mixed.
Freeze the ice cream according to the manufacturer’s instructions.
While it freezes, slice up a peach or two.
When the ice cream is ready, line the bottom of a bowl or ice cream mold with some of the peach slices.
Pour some of the ice cream mixture in, smooth the top, then add more peaches.
Cover the bowl or mold tightly and place in the freezer for several hours.
When the ice cream is firm, unmold it onto a plate or wrap the mold in a hot towel to help it release.
Garnish the ice cream with more sliced peaches and the strained peach puree.
