Non-Cream Ice Cream

Our answer

Your sister's allergy is interesting as your comments seem to imply that the fat content is the thing that triggers the allergy, rather than being a more straightforward dairy allergy or intolerance. Consequently we are not sure if she is able to tolerate soy-based whipping cream products.

Assuming that she can tolerate soy-based whipping cream then you could certainly try using this as an alternative. The UK has a product called Cremo Vita (made by Granovita) and the US has a range of products made by SoyaToo. You cold try this for Nigella's No-Churn Pomegranate Ice Cream which is suitable Christmassy. See the related recipe link for the original recipe.

If she can tolerate regular milk then you could make a classic custard ice cream base using full fat (whole) milk and the soy product and then churn it as normal ice cream. Or you could try using a whipped topping dessert, such as Dream Topping in the UK or Cool Whip in the US, though please note that these prodcts do contain some dairy ingredients. These could be folded into a can of chilled condensed milk to make Nigella's One Step Coffee Ice Cream from Nigellissima.

Please note that it is very imprtant that you check with your sister that she can tolerate the ingredients before you use any of them. Also we have not tested the recipes with these alternative ingredients so cannot guarantee results.