Yields 5 cups
Prep time: 1 hour
Cook time: 10 minutes
INGREDIENTS
For the Butter:
1 cup buttermilk
3 cups heavy cream
2 cups distilled white vinegar
¼ cup granulated sugar
2 tablespoons kosher salt
3 serrano chiles
1 red bell pepper, seeded and cut into ½-inch dice
½ medium yellow onion, very thinly sliced
1¼ cups small (about ½-inch) cauliflower florets
1¼ cups very thinly sliced carrots (about 3 medium carrots)
2 medium celery stalks, very thinly sliced (about 1 cup)
2 garlic cloves, finely chopped
1 tablespoon whole yellow mustard seeds
1½ teaspoons dried oregano
¼ cup olive oil
Sourdough, toasted
DIRECTIONS
In a stand mixer, whip the buttermilk and heavy cream on medium-high speed until the solids separate, 10 to 15 minutes. If you're worried about any spillage, tightly wrap the top of the bowl with plastic wrap. (Reserve the leftover buttermilk for another use.)
Build an ice bath using 4 cups of cold water and 2 cups of ice.
Place the butter solids in a fine-mesh sieve set over a large bowl.
Spoon ½ cup of ice water over the butter and gently knead (like dough) to remove all of the remaining buttermilk. Knead and rinse until the liquid that seeps out is clear and all of the water is removed.
Place the butter on a piece of wax paper and roll into a log. Chill in the fridge to firm.
Make the giardiniere:
In a medium pot, combine the vinegar, sugar and salt, and bring to a boil. Add the chiles and cook until they are cooked through and the green color begins to dull, 8 to 10 minutes. Remove from the heat and allow the chiles to cool completely in the vinegar.
When the chiles are cool, slice into ¼-inch-thick rounds. Reserve the pickling liquid.
In a mixing bowl, combine the pickling liquid with the sliced chiles and all remaining ingredients (except the bread). Allow to marinate for 1 to 2 days before serving. Place in an airtight container and keep in the fridge for up to 2 weeks.
Spread some butter over a piece of warm sourdough toast.
Top with the giardiniere and serve.
