Sweetbreads with a Balsamic Mustard Demi-glace and Roasted Shallots
Tender sweetbreads are dusted with flour, browned, and finished in the oven. They are served with a demi-glace sauce flavored with balsamic vinegar and Dijon mustard. Red onions, cooked until they are charred and caramelized, are sliced and fanned as an unusual garnish.
- Roasted Shallots
- Shallots - 18, peeled
- Olive Oil - 1/4 cup
- Peppercorns - 1/2 tablespoon, coarsely ground
- Sweetbreads - 2 pounds
- Onion - 1 small, quartered
- Carrot - 1, chopped
- Celery Stalk - 1, chopped
- Garlic Cloves - 3, smashed
- Bay Leaf - 1
- Peppercorns - 1 teaspoon
- Balsamic Mustard Demi-glace
- Shallots - 3, chopped
- Mustard Seeds - 1 tablespoon
- Balsamic Vinegar - 1/2 cup
- Red Wine - 1/2 cup
- Demi-glace - 1 cup demi-glace
- Heavy (whipping) cream - 2 to 3 ounces
- Unsalted Butter - 1 tablespoon
- Dijon mustard - 2 to 3 tablespoons, to taste
- Charred Red Onions
- Olive Oil - 2 tablespoons
- Red Onions - 3 small
- Flour - 1/2 cup
- Salt - 1/2 teaspoon
- Freshly ground black pepper - 1/2 teaspoon
- Savory Sprigs - 6
- Thyme Sprigs - 6
- Fennel Frond - 1
To roast the shallots: Preheat the oven to 350 F. Put all ingredients in an ovenproof pan and toss the shallots to coat with the oil. Cover and bake until tender, 45 to 60 minutes, depending on size. Remove the lid and bake 10 more minutes to brown. Remove from oven and strain to remove the oil; reserve the oil and shallots separately.
To prepare the sweetbreads: Put all ingredients in a large sauce pot and add enough water to cover the sweetbreads. Bring to a boil over high heat; remove the pot from the heat and add enough ice to quickly cool the mixture. Set aside.
To prepare the demi-glace: Put the shallots, mustard seeds, vinegar, and wine in a medium saucepan and boil over medium-high heat until the liquid is reduced to 2 tablespoons. Reduce heat to medium and add the demi-glace; cook until the sauce starts to thicken, then remove from heat. Stir in the cream, butter, and mustard. Strain through a fine-meshed sieve and set aside.
To prepare the charred onions: Preheat the oven to 400 F. Heat the oil in a medium ovenproof skillet over medium-high heat and brown the onions on all sides. Place in the oven and cook until charred on the outside and tender throughout, 30 to 45 minutes. Remove and set aside.
To finish the sweetbreads: Preheat the oven to 400 F. Mix the flour, salt, and pepper together. Remove the sweetbreads from the liquid and remove the membranes from the sweetbreads. Break into individual lobes or pieces. Dust with the seasoned flour. Heat the reserved shallot oil in an ovenproof saute pan over medium-high heat; if there is not enough oil to coat the pan, you may add olive oil as needed. Sear the sweetbreads on all sides. Put in the oven for 10 to 12 minutes, or until done through. Remove and let rest 3 minutes.
To serve: Cut the charred onions in half vertically, then slice each half vertically almost all the way to the top. Pool demi-glace on each individual serving plate. Spoon roasted shallots around the sauce. Arrange sweetbreads over the sauce and shallots. Fan half a charred red onion on each plate and garnish with sprigs of savory, thyme, and a few pieces of fennel.