Ever since I first saw the commercial for New Shimmer, I've had an appreciation for desserts that pull double duty. And if we can make a dessert topping that shines floors like no other, we can make ice cream that tastes and slices like pie.
For reference, if I've lost you, here's the video.
Now let's talk pie. We have an excellent key lime pie on this site, and a super-easy, sweet and salty icebox lime pie for those pressed for time. This pie is a hybrid of both: a real graham cracker crust filled with sweet-tart lime ice cream, and even easier, cooler, and more refreshing than your standard pie. And even better: it doesn't require an ice cream maker.
The ice cream couldn't be easier: lime juice, heavy cream, and sweetened condensed milk, which when stirred together form a thick, creamy, insta-custard as the lime partially curdles the dairy. Don't worry, there are no clumps of curdled dairy here; the Brits have been making similar acid-based custards called possets for centuries to good results.
The custard is so thick and creamy that you don't even need to churn it. I've compared churned and unchurned versions, and apart from a smidge more iciness and a difference in volume (the churned version has more air), the unchurned one is just as good. As for the limes, you can use key limes if you got 'em, but this recipe is formulated for plain old supermarket limes. The crust is the same as you'll find in our key lime pie recipe, and I see no reason to improve upon it.
Why does this ice cream—which doesn't even have eggs—work so well without a machine? It's a thick custard with an exceptionally high butterfat content—more than most premium ice creams—and it gets plenty of smoothness from sweetened condensed milk. It plays by its own rules, and the absence of eggs lets the lime juice, zest, and condensed milk stand out even at freezer temperatures.
You can store this pie in the freezer for a few days until it's ready to serve, but after that the flavor and texture of the ice cream will begin to slump. I don't think you'll have trouble finishing it quickly.