In a medium bowl, combine the diced peaches with 1/2 cup of sugar. Let the mixture sit for about 30 minutes to allow the peaches to release their juices.
After 30 minutes, mash the peach mixture with a fork or potato masher until it reaches your desired consistency (smooth or chunky).
In a separate large bowl, whisk together the heavy cream, whole milk, remaining 1/2 cup of sugar, vanilla extract, lemon juice, and a pinch of salt until the sugar is dissolved.
Stir the mashed peach mixture into the cream mixture until well combined.
Pour the mixture into an ice cream maker and churn according to the manufacturer's instructions, usually about 20-25 minutes.
Transfer the churned ice cream to an airtight container and freeze for at least 4 hours or until firm.
Before serving, let the ice cream sit at room temperature for about 5-10 minutes to soften slightly.