I followed the recipe for the most part, but we only had half as much asparagus as called for, which would be one of those bundles from the market, I think. I used the four cheese blend I always buy, rather than the two cheeses he suggests, and I used somewhat less, thinking a baggy full must be enough. I also used a regular short crust pastry rather than going out for phyllo. This tart is good! We will do it again.
Tips: put a sheet pan under the tart pan. Butter dripped all over the oven; what a mess! Next time I will try the phyllo crust and do it all the way it is written. More asparagus for sure! I do think it would be fine to substitute milk or half and half for the cream, and that a little less cheese is fine. However, I am debating with myself between using a stronger cheese, maybe the delicious Portuguese cheese I occasionally by at the farmer's market, or sticking with what I used this time. The balance of flavor is delicate and I wouldn't want to overwhelm the potato and asparagus. Not sure, but this was really good. : )