Stir sugar and cornstarch in heavy medium saucepan.
Whisk in milk
and cream. Whisk over medium heat until gelato base thickens and
begins to bubble, about 5 minutes. Pour into bowl. Cool over ice,
Puree strawberries in processor. Mix in lemon juice.
Chill 3 hours.
Process in ice cream maker according to manufacturer’s instructions.
Transfer to container. Cover; freeze until firm, at least 3 hours
and up to 2 days.