Who doesn’t love sweet potatoes? Culinary gravity inexorably pulls them toward brown sugar or molasses or something candied, even with bacon (candied bacon). But don’t do it, at least not this time. I never encountered a sweet potato during my year abroad in the Swiss canton of Fribourg, a stone’s throw from the town of Gruyères (town, plural: cheese, singular), but I can guarantee that that if there were ever a culinary match made in heaven it’s sweet potato and that most hazelnut and butter flavored of all cheeses, aged Gruyère. Some cheeses should never be melted (sorry, brie en croute is ghastly) but Gruyère is just the opposite. Quiche, the poster child of boring French food from the ’70’s, is redeemed by the addition of aged Gruyère. Fondue without Gruyère is but a pale revenant of the real deal. Gruyère is expensive (around $20/lb.) but the recipe only calls for a cup and half of the stuff, grated, about 3 ounces. Unfortunately, I only found out about the Gruyère after the ingredients photograph had been taken. Jody announced that she’d added Gruyère–I couldn’t even photograph it being stirred into the bowl. I growled and stomped around. I should have waited until I tasted the finished pie. Gruyère and sweet potatoes rule.
culinary epoch. Boring. White. Food. But a tart, a tart can play. Sweet or savory, rich or light, it has no rules beyond the obligatory crust, and inclination to use whatever looks good in the market that day. And what looked good to us was the Swiss chard. So, yes, this is a savory custard tart, but it’s really about the chard. Oh, and the anchovies. The tart doesn’t taste like anchovies–it tastes like chard, with cream and cheese, and something salty and elusively delicious in the background. 
The Garum Factory 