Step 1In a large, heavy saucepan, combine the cream, milk and 8 geranium leaves. Heat the mixture over medium-high heat until it comes to a simmer, then remove from heat, cover and set aside to steep for 1 to 2 hours.
Step 2In a large bowl, combine the sugar with the remaining leaves. Rub the leaves and sugar between your fingertips to release the oils, rubbing the leaves until they are very soft and fall apart.
Step 3Return the cream mixture to a simmer. Meanwhile, beat the egg-yolk-and-sugar mixture in the large bowl until light. Gradually whisk in the hot cream mixture to temper the eggs. Return the cream mixture to the saucepan and stir constantly over low heat until the custard thickens to coat the back of a spoon, about 8 minutes, careful not to boil. Strain the custard into a bowl set over a bowl of ice water and gently stir until completely cooled.
Step 4Transfer the custard to an ice cream maker and freeze according to the manufacturer's directions. This makes about 1 quart ice cream.
Step 1In a small, heavy saucepan, combine the water, sugar and 6 rose geranium leaves over medium-high heat and bring to a boil. Cook until the leaves are wilted and the liquid is reduced to a scant ½ cup, about 4 minutes. Cool completely, then strain the syrup into a jar. The syrup will keep, covered and refrigerated, for up to 2 weeks.
Step 2Toss the berries with enough syrup to sweeten to taste. Serve the ice cream topped with the berries and garnished with additional rose geranium leaves.