Made these 3x now and I'm still trying to perfect the custard part. Tastes delicious but the custard isn't as smooth as I'd like. The custard continues to cook after you take it off the stove, so take it off a little early. Also, have the tarts ready and do the custard last because as it cooks and cools down it keeps thickening.
As for the tart part, contrary to the image, I rolled my thawed pastry dough out into a square and then rolled that into a log. I cut disks about 1/2" thick and rolled those out into circles to line the muffin tin.
Recipe was a hit!