Combine the cream and 1½ cups of the milk in a medium saucepan and bring to a simmer over medium heat.
While the cream/milk heat, combine the remaining milk, sugar, cornstarch and salt in a mixing bowl using a whisk to mix well.
Puree the strawberries in a blender or food processor until smooth, then set aside and reserve.
As soon as the cream/milk comes to a simmer, add the milk/sugar mixture and whisk until combined. Turn up the heat a little to bring this mixture to a boil while continuously whisking.Once it comes to a boil, turn down the heat to a simmer and let this cook down until it thickens enough to coat the back of a spoon. This will take 10 to 15 minutes depending on your stove top.
Remove the saucepan from the heat and add the pureed strawberries, vanilla and straw berry jam.
Cover and refrigerate for a minimum of 2 hours or overnight.
Before you add the chilled mixture to ice cream maker, whisk it well to combine all the ingredients.
Add the gelato mixture to the ice cream maker and follow the manufacturer’s instructions for preparing gelato.
For my Cuisinart Commercial Quality & Gelato Maker, this means using “gelato paddle” and mixing for 30 to 40 minutes until thickened. The gelato will be soft at this point and reading for serving but I like my gelato a little firmer so I stick it into the freezer in an airtight container for an hour or two to firm it up.
According to the Cuisinart directions, you should remove the gelato from the freezer 15 minutes prior to serving to let it soften up some. I can make it no more than 5 minutes before jumping into it.
I have read the longer you let the mixture sit, the more flavorful the gelato but I can’t tell you that from experience because I have only let it sit in the refrigerator for 4 hours.