A hybrid dish (cua means “crab” in Vietnamese, and farci means “stuffed” in French), this deviled crab is enriched by butter and employs fish sauce to amplify the brininess of the crustacean. Many cooks stuff the crab shells with the raw filling and then fry them. Because it is hard to tell when the filling is cooked, I was taught to sauté it first, which also yields a more flavorful result. I also forgo frying and instead bake the filling in ramekins, topping them with bread crumbs for a crispy finish. What makes this deviled crab special is fresh crabmeat and tomalley (liver) and fat, which you can only get if you start with a whole crab. (If you don’t like the tomalley and fat, omit them for a less rich dish.) Find the freshest, feistiest crab you can, even if it is not a Dungeness, my local species. Live crabs are available at Asian and other markets, but already cooked crabs will work, too—as long as you have a trustworthy fishmonger. Ask when the crab was cooked. And if it has an ammonia-like smell, it is over the hill, so pass it up. You will need about 1/2 pound of crabmeat.
You can prepare this dish a day in advance. Make the crab mixture, fill the baking dishes, cover, and refrigerate. Let the dishes sit at room temperature for about 30 minutes before brushing the tops with egg yolk, sprinkling with bread crumbs, and baking.
