Cook's Illustrated

Introducing French Onion Tart

Published January 1, 2007.

French Onion Tart is similar to quiche but delivers a more refined slice of pie, with more onions than custard. The problem? Rolling and fitting the dough into a tart pan.

The Problem

Re-creating an onion tart at home can produce a tough and crackery crust, which is doubly disappointing after spending long hours delicately cooking the onions, making the custard, and baking the whole thing together.

The Goal

We wanted to simplify the crust and shorten the overall preparation time.

The Solution

We found that our onions would cook in half the usual time if we left the lid on the skillet throughout cooking. And covering the onions allowed them to cook entirely in their own juices, thereby becoming tender, retaining their pure onion flavor, and cooking more evenly. We liked bacon, which acted as a crisp foil to the creamy filling, but we found a traditional custard with the bacon to be simply too rich. To solve the issue, we reduced the number of eggs and switched out the cream for half-and-half. We tried several classic crust recipes, looking for one that had the intense butteriness of traditional tart dough but could still be easily patted into a tart pan. We found that using a food processor to cut cold butter completely into the flour mixture required less ice water than a conventional crust, which kept the dough firm enough to press into the pan.

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