These soy-marinated duck breasts are a standard item in my Osechi (Japanese-style New Year foods).
Duck breasts would be available in some grocery stores, such as Whole Foods Market, Papa Joe's and Peacock, at frozen meat section.
Soy-Marinated Duck Breasts
12oz (2 fillets) boneless duck breasts
2 inches kelp (see a note below)
1/4 cup hot water
1/8 cup white wine
1/8 cup maple syrup
1/4 cup soy sauce
In a saucepan the duck breasts just fit, reconstitute the kelp in the hot water for a couple of minutes. Add the white wine, maple syrup and soy sauce.
Using a sharp knife, score the duck skin on diagonals to make a diamond pattern. Pat them dry with paper towels.
In a non-stick skillet over medium-high heat, add the duck, fat side down, and sear until crispy for about 5 minutes. Then flip and cook for 30 more seconds.
Add the duck to the saucepan with a lid on, bring to a boil, reduce the heat over low and cook for 5 minutes. Turn off the heat and let cook at room temperature.
Transfer to a Ziplock bag, both the duck and the sauce, and marinate in fridge overnight.
Slice thin and arrange on a plate. Spoon the sauce over or place alongside for dipping.
Serve at room temperature.
Note:Kelp (or Kombu) is a kind of seaweed and available in Whole Foods Market and Japanese grocery stores like Noble Fish.