Mini Duck Burgers with Shiitake Mushroom Ketchup and Chinese Mustard Sauce

YIELD: 4 servings (8 2-oz. patties)

For Mongolian marinade:
½ cup hoisin sauce
1 ½ tsps. sugar
2 ¼ tsps. tamari
2 ¼ tsps. sherry vinegar
2 ¼ tsps. rice vinegar
1 to 2 scallions, white and light green parts only, minced
½ tsp. Louisiana style hot sauce
¾ tsp. black bean chili sauce or hot garlic sauce
¾ tsp. grated fresh ginger
2 ¼ tsps. minced garlic
¼ to ½ tsp. minced cilantro leaves and tender stems
1 ½ tsps. sesame oil
For duck burgers:
1 lb. ground duck
1 scallion, white and a bit of the tender green, minced
1 tsp. minced fresh ginger
1 ½ tsps. minced garlic
1 tsp. salt
¼ tsp. fresh ground black pepper

For shiitake mushroom ketchup:
2-3 Tbsps. olive oil
1 lb. shiitake mushrooms, stemmed and quartered
1 onion, finely diced
½ tsp. salt
½ tsp. fresh ground black pepper
¼ cup balsamic vinegar
2 tsps. minced garlic
2 Tbsps. molasses
¼ bunch basil leaves, chopped
¼ cup Mongolian marinade

For Chinese mustard sauce:
¼ cup sugar
2 Tbsp. mustard powder
1 large egg yolk
¼ cup red wine vinegar
6 Tbsps. crème fraiche or sour cream

To serve:
Additional Mongolian marinade, for basting 8 small sesame brioche buns

1.    For the marinade: Whisk together all marinade ingredients in stainless steel bowl.
2.    For burgers: Combine all duck burger ingredients in large bowl and mix well. Cover and refrigerate at least 1 hour and up to overnight.
3.    For ketchup: Sauté mushrooms until tender. Add onions and cook until translucent. Add remaining ketchup ingredients and reduce until mixture will coat the back of a spoon. Refrigerate until ready to use and heat to serve.
4.    For mustard: In double boiler, combine sugar and mustard powder. Whisk to blend thoroughly. Whisk in egg yolk and vinegar. Whisking constantly, cook until the mixture is thick enough to ribbon. Cool mixture and add crème fraiche or sour cream. Keep refrigerated.
5.    To serve: Portion chilled duck mixture into 2 oz. mini patties.
6.    Grill or griddle patties to order over medium-high heat 2-3 minutes per side, basting with marinade. Toast and lightly butter buns. Place burgers on bun bottoms, and top each with shiitake ketchup, arugula and a drizzle of Chinese mustard sauce. At the top bun and serve with extra ketchup and mustard on the side.