A rich roasted-vegetable demi-glace has been sought after by chefs in restaurants, cooks at home, and even those in large-scale commercial operations. For several reasons, it’s an elusive concept. Vegetables tend to add sweetness to stocks, so reduced vegetable stocks tend to be very sweet. Vegetables also don’t have collagen, which plays a massive role in the mouthfeel of a final reduction. Our ultimate goal is a refined sauce that can stand up to any demi-glace comparison.
Roasted Vegetable Demi-Glace
Chef Jamie Simpson
Here, we shave a bunch of vegetables and roast them for nearly an hour and a half, until almost dry and slightly bitter, and then steep them. Later, we strain, reduce, and thicken the mix with pectin to create the required mouthfeel. You will be amazed by its depth of flavor.
1 large red onion
- 5 large garlic cloves
- 1 leek
- 2 parsnips
- 2 carrots
- 1 golden beet
- 3 sunchokes
- 1 eggplant
- 1 kohlrabi
- 3 celery stalks
- 1 head of cauliflower
- ½ cup (120 ml) tomato paste
- Vegetable oil
- 8 cups (2 L) filtered water
- 3 bay leaves
- 1 bunch thyme
1 tablespoon (12 g) pectin powder
Preheat the oven to 350°F. Line two large rimmed baking sheets with foil.
- Using a mandoline slicer or other slicer, thinly shave all the vegetables, keeping the onion, garlic, and leek in a separate bowl from the others.
- In a large bowl, whisk the tomato paste with just enough oil to loosen it to the consistency of pesto. Add the onion, garlic, and leek and toss, then spread the mixture on one side of one of the baking sheets.
- Drizzle some oil on the remaining vegetables and toss to coat well. Spread the vegetables on the remaining spaces on the 2 baking sheets.
- Roast the vegetables for 40 minutes, stirring every 20 minutes, until the onion, garlic, and leek are well browned. Scrape the onion mixture into a stockpot. Continue roasting the remaining vegetables, stirring every 20 minutes, until they are very dark but not burnt, and are mostly dehydrated, about 40 minutes longer.
- Transfer the roasted vegetables to the stockpot. Add the water, bay leaves, and thyme; cover and bring to a simmer, then reduce the heat to low and cook gently for 1 hour. Strain through a fine-mesh strainer into a bowl; whisk in the pectin. Return the stock to the pot and bring to a simmer over medium heat. Simmer until concentrated, viscous, and reduced to 4 cups. Stock can be refrigerated for up to 10 days or frozen for several months.
If some of these vegetables are unavailable or you have others aging in your refrigerator, substitute them. Just avoid red beets, purple carrots, leaves of any sort, starchy vegetables like potatoes and sweet potatoes, or watery vegetables, like cucumbers.