French for "burnt cream", this is a creamy custard with a thin layer of caramelized sugar on top. The combination of textures and flavors is fun to eat, but it's even more fun to make: burning the sugar is a great way to cap off a dinner party.
There are roughly 4 techniques for burning the sugar on top:
Hot iron held on top --> old school, takes a while, I don't think anybody does this anymore
Broiler --> heats up the custard a lot, isn't quite as satisfying
Handheld butane torch --> this is probably the most appropriate method for doing this at home
Large butane torch --> what restaurants do, probably not appropriate for home chefs
You can get handheld butane torches at various hardware, camping, or cookware stores. I got my torch as part of a set that included ramekins as well (I can't find the same set anymore but the BonJour Chef one is not that different)
This is adapted from Cook's Illustrated, and serves ~4-6 people depending on the size of your ramekins (I prefer the smaller ramekins, especially since most people don't want a huge portion after dinner):
2 cups heavy cream
1/2 vanilla bean (or 1 tsp extract)
1/3 cup sugar
pinch salt
6 large egg yolks
extra sugar for the top (as noted later, turbinado/raw/demerara works best)
300° oven
half the cream with the sugar, salt, and vanilla bean--boil until sugar dissolves, then steep for 15 min
boil water (for water bath)
stir in other half of cream...slowly incorporate egg yolks and strain
make water bath (towel underneath helps avoid sloshing) & pour custard mixture in; bake until barely set/no longer sloshy (25-35 min), center should be 170-175°
wait 2 hours (or until room temperature)
4 hours to 4 days in fridge
put sugar on top, caramelize...optionally re-refrigerate max 30-45 min to firm everything up, but you can also just eat as soon as the top hardens
...but the Cook's Illustrated version is pretty creamy/rich. Some folks prefer a lighter version; for example, Serious Eats did some experiments and preferred a 1:1 ratio of cream and milk (their version isn't wildly different but basically would be 3/4 cups each milk and cream + 7 yolks + 1/2 cup sugar, otherwise the same)
Best recipe: Cook's Illustrated, as always, offers a good recipe discussed here in a side by side comparison
How-to Photos: Cooking for Engineers also gives a recipe with nice pictures
Torching Video: Cuisine at Home has a good video of how to torch the sugar—the key is moving nice and slow
Lots of discussion about what kind of sugar to use, but I think the CI folks' idea of using "turbinado" or "demerara" sugar (basically raw cane sugar, available in the U.S. under the "Sugar in the Raw" label) gives a deeper taste than refined "white" sugar, without brown sugar's moisture (which ruins the crispiness).