Mushroom Ketchup

When we consider ketchup, we tend to think only of the sweet-and-tangy tomato-based concoction. Yet ketchups have in fact been around for a long time, and other varieties—notably mushroom and walnut—preceded the now ubiquitous tomato ketchup by at least one hundred years. Ketchup originated in China—early versions of the table sauce were based on pickled fish—and made its way with explorers and traders back to Europe, eventually arriving in the New World colonies. The combination of acidity, sweetness, spice, and heat played right into the burgeoning Southern palate.
Over time the tomato became the preferred main ingredient in American ketchup, but I love variations, like this one, that hark back to ketchup's earliest incarnations. Preparing it at home reminds me that it is more similar to classic pickling than it is to sauce making. Note that some of the mushrooms must sit overnight so that they soften sufficiently.

Ingredients:

1 cup red wine vinegar
2 tbsp. natural cane sugar
½ lb. button mushrooms, coarsely chopped, plus 1/2 cup sliced button mushrooms
2 oz. dried shiitake mushrooms
1 tbsp. kosher salt
1 whole allspice
¼ tsp. whole fennel seeds
1 bay leaf
¼ tsp. crushed red pepper flakes
1 cinnamon stick
1½ tsp. grapeseed or canola oil
½ medium onion, thinly sliced
1 clove of garlic, chopped
2 tbsp. sorghum

Preparation:

In a medium saucepan, bring the vinegar, 3 cups water, and the cane sugar to a boil over medium-high heat, stirring to dissolve the sugar. Remove the pan from the heat and stir in the 1/2 lb. chopped mushrooms and dried shiitakes. Cover and let sit at room temperature overnight.

In a large saucepan, stir together the sliced mushrooms, salt, allspice, fennel seeds, bay leaf, red pepper flakes, cinnamon stick, and 2 cups water. Let sit at room temperature for 20 minutes. Cover and bring to a boil over high heat. Remove from the heat and let sit, covered, for 30 minutes. Strain through a chinois or fine-mesh sieve, pressing on the solids to remove as much liquid as possible. Discard the solids and set aside the mushroom stock.

In a large saucepan, heat the oil over medium heat. Add the onion and garlic and cook, stirring often, until very soft and caramelized, about 15 minutes. Add the reserved mushroom stock and stir with a spatula to scrape up the browned bits from the bottom of the pan. Add the reserved mushrooms with their liquid and the sorghum.

Bring to a boil over high heat, reduce the heat to medium low, and simmer, stirring occasionally, until all but about 1 cup of the liquid cooks away, about 2 hours. Discard the bay leaf.

Pureé the mixture in a blender, in batches if necessary. Add a little water if necessary to keep the mixture moving. Let cool to room temperature. Transfer to an airtight container, cover, and refrigerate for up to 1 week