Oh, this dish sounds so romantic in French — Gésiers de Canard Confit — duck gizzards, slowly cooked in duck fat. When cooked confit, strong muscle of gizzard becomes a soft and plump morsel, full of flavor, with a hint of gaminess. Gésiers de canard confit is a specialty in South West France that pleasantly surprises many tourists who try it for the first time. Gésiers are respected ingredient in a variety of warm salads, including famous Landaise salad. They are gently fried in a little duck fat before serving. They are also very good with buckwheat, roasted potatoes, or sautéed winter squashes.
The recipe below is for duck gizzards, but the same instructions are good for hearts, chicken or duck, with the exception for timing. Chicken hearts are cooked faster, they only need 1 hour in the oven. Turkey gizzards and hearts are larger and need 20-30 minutes more, accordingly.
Place clean trimmed duck gizzards in an oven proof dishes, season, add duck fat and herbs, cover with foil and cook in oven for 2.5 hours.
Strain gizzards and store them in a closed container until ready to use, refrigerated. Store strained liquid, duck gizzards stock, in a separate container, also refrigerated. When the stock cools down, duck fat will be collected on the top of a gelatinized stock, which is delicious. Do not discard fat! It can be used for frying gizzards before serving.
Cooked gizzards can be served whole, sliced in half, or thinly sliced. They should be room temperature, or warm. You can bring them to room temperature by taking out of refrigerator in advance, by using microwave (in closed container), or by gently frying them in duck fat.
In the U.S., the best food stores to look for duck gizzards are Asian supermarkets. In Austin, look for them in MT Supermarket in Chinatown.
If you buy the whole duck, use its skin trimmings to render fat. Render it slowly for the best results. If you get duck gizzards only, buy duck fat separately in Central Market, meat department.