Many chefs cook fruit to accompany fresh foie gras, which we love, but Gerard and I have always preferred to serve it with sweet caramelized onions—a recipe we learned while vacationing in Béarn years ago. You can make the onions and slice the foie gras in advance. Keep the foie gras slices refrigerated and the onions in the pan, where they need to be warmed up before serving. Invite the guests to the table before finalizing the dish. As with a soufflé, the guests wait for the food, the food does not wait for the guests.
5 large onions, yellow, white, or red
3 tablespoons olive oil
1 teaspoon salt
2 tablespoons sugar
1 Grade-A duck foie gras, in ½ inch slices
6 slices white bread
Caramelizing the onions
Slice off the root and top ends of the onions, and peel the onions. Cut them in half. Lay them cut side down and slice them lengthwise to about quarter inch thickness.
Use a wide, thick-bottomed sauté pan for maximum pan contact with the onions. Coat the bottom of the pan with olive oil. Heat the pan on medium-high heat until the oil is shimmering. Add the onion slices and stir to coat the onions with the oil. Spread the onions out evenly over the pan and let cook, stirring occasionally. Reduce the heat to medium to prevent the onions from burning or drying out. After ten minutes, sprinkle the salt over the onions and add the sugar to help with the caramelization.
Let cook for 30 minutes to an hour more, stirring every few minutes. To keep the onions from drying out as they cook, add a little water to the pan (1/4 cup). As soon as the onions start sticking to the pan, let them stick a little and brown, but then stir them before they burn. The trick is to let them alone enough to brown (if you stir them too often, they won't), but not for so long that they burn. After the first 20 minutes, turn temperature to medium-low. As the onions caramelize, scrape up the browned bits from the bottom of the pan with a spatula. As the onions cook down, you may you need to scrape the pan every minute instead of every few minutes. Continue to cook and scrape, cook and scrape, until the onions are a rich, browned color. At the end of the cooking process, take the pan away from the heat , remove the onions and add a spoonful of balsamic vinegar to help deglaze the pan, and then put the onions back in to absorb the added flavor.
When the guests are seated, excuse yourself and pop the bread in the toaster. (I have Gerard serve the wine; he usually talks about the wine long enough to divert everyone’s attention while I prepare the dish—that’s teamwork.) Warm up the onions for two minutes. Spread the onions over the toast and place a slice of toast onion-side-up on each dish.
Sauté the Foie Gras
Season the foie gras with salt and pepper, and then dredge it lightly in flour. Heat a heavy bottom pan on high heat. When the pan is very hot, add the foie gras slices and lower the heat to medium-high. Sear until the foie gras slices are dark brown ( a couple of minutes). Turn them over and cook on the other side until fully cooked but still soft to the touch. Top off each toast with the foie gras. Serve all of it; if it is too abundant, add pieces beside the toasts.