From: Chef Michael Shackelford, formerly of Trelio Restaurant, Clovis, CA. Yield: 4 servings.
Grape Aigre Doux:
2 cups slightly sweet white wine (Riesling or Gewurztraminer)
¼ cup champagne vinegar
½ cup sugar
2 tsp. fresh ground pepper
1 tsp. kosher salt
½ tsp. vanilla extract or a vanilla bean sliced in half and scraped
4 cups seedless red grapes
Pickled Black Mustard Seeds:
2/3 cup black mustard seeds
1 cup champagne vinegar
1 Tbsp. sugar
1½ tsp. sea salt
½ tsp. freshly ground Penja white pepper (Muntok or Sarawak will work also, but must be freshly ground)
1 lb. sweetbreads
½ cup saba (grape must reduction)
1/8 cup sugar
1 gallon cold water
1 cup white wine vinegar
2 Tbsp. kosher salt
2 Tbsp. clarified butter
Apple-Celery Root Puree:
1 lb. celery root, peeled and cubed 1”
3 cups lowfat milk
1 tsp. kosher salt
2 Tbsp. arborio rice
1 large Granny Smith Apple, peeled and quartered
2 tsp. butter
For grape aigre doux: In a heavy-bottomed pot over medium-high heat, bring wine, vinegar, sugar, salt and pepper to a boil. Add vanilla extract or vanilla bean. Lower heat to medium and allow to simmer for 2 minutes. Remove vanilla bean, if used. Lower heat to low and add grapes; stir and cook for 10 more minutes. Place in an airtight container in refrigerator until ready to use, up to a week. Yields 2 pints.
For pickled black mustard seeds: Place mustard seeds in a medium saucepan and cover with cold water. Over high heat bring to a boil, stirring occasionally. Drain seeds in a fine strainer. Repeat process 9 more times. In a medium saucepan, combine vinegar, sugar and salt and bring to a boil. Let cool and add blanched mustard seeds and freshly ground white pepper. Place in a nonreactive container and refrigerate for two days before using.
For sweetbreads: Soak sweetbreads in cold water for 6 hours, or until they have turned white, changing the water every 2 hours. Place sweetbreads in colander to drain. Transfer to a large pot and add the cold water, vinegar and salt. Bring to a boil, reduce heat to a simmer for 10 minutes. Drain and place in an ice bath to stop the cooking.
In a small saucepan, bring saba and sugar to a boil. Reduce by a third and remove from heat.
Break up the sweetbreads into one-inch blocks making sure to remove any sinew or skin. Season each piece lightly with salt and pepper. Over high heat, preheat a large sauté pan. Add clarified butter, bring to temperature and add sweetbreads. Sauté until lightly browned. Add saba reduction to pan, reduce heat and toss sweetbreads until completely glazed. Remove from heat.
For Apple-Celery Root Puree: Place the celery root in a medium saucepan, add the milk, ½ tsp. salt, and a grinding or two of pepper and bring to a boil over moderate heat. Stir in the rice, lower the heat, partially cover and simmer for 10 minutes. Add the apples and simmer for 10 minutes longer, or until the celery root is very tender. (The milk will curdle, but curds will be incorporated when the celery root is pureed.) Drain mixture in a colander set over a bowl; save cooking liquid.
Puree celery root and apple solids in a food processor until smooth. Add a few tablespoons of cooking liquid if still chunky after a minute. Process for a few more minutes until ingredients resemble a very thick soup. Season with remaining salt and more pepper to taste.
For service: On a plate, lay a base of the celery root-apple puree. Place sweetbread pieces and strained grape aigre-doux (no liquid, just the grapes) on top of puree. Garnish with herbs and pickled mustard seeds.